<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2020 Workiva-->
<!--r:8437cf04-ceaf-47ab-959d-e709aa483b5a,g:6ad5ee9d-67d5-4758-a4a1-902d0ec9d373-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef roleURI="http://www.fcbanking.com/role/CoverPage" xlink:type="simple" xlink:href="fcf-20200331.xsd#CoverPage"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CoverPage" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofFinancialConditionUnaudited" xlink:type="simple" xlink:href="fcf-20200331.xsd#CondensedConsolidatedStatementsofFinancialConditionUnaudited"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofFinancialConditionUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndDueFromBanks_b4ff6ec7-fbc6-44ab-9a87-3bf995912979" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndDueFromBanks"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_CashAndDueFromBanks_b4ff6ec7-fbc6-44ab-9a87-3bf995912979" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositsInBanks_f2e983d4-9764-47d8-861a-35834ffd225d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestBearingDepositsInBanks"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_InterestBearingDepositsInBanks_f2e983d4-9764-47d8-861a-35834ffd225d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecurities_cb0c5c59-d7b6-4a8c-8130-17d0f371f2d0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecurities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_AvailableForSaleSecurities_cb0c5c59-d7b6-4a8c-8130-17d0f371f2d0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesNoncurrent_28060a15-2996-4361-92de-efe63e67fba0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HeldToMaturitySecuritiesNoncurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesNoncurrent_28060a15-2996-4361-92de-efe63e67fba0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherInvestments_a397096a-b2d0-4aed-8059-c8e5593646f5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherInvestments"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_OtherInvestments_a397096a-b2d0-4aed-8059-c8e5593646f5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup_00b2422f-c70f-457a-a807-9b1fb5c1477f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_LoansReceivableHeldForSaleNetNotPartOfDisposalGroup_00b2422f-c70f-457a-a807-9b1fb5c1477f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableNetReportedAmount_363e7025-d116-4c0d-b8d2-d4e126d17644" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LoansAndLeasesReceivableNetReportedAmount"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_LoansAndLeasesReceivableNetReportedAmount_363e7025-d116-4c0d-b8d2-d4e126d17644" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_1b3d026c-6946-438b-bbf1-53557a7a5beb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_1b3d026c-6946-438b-bbf1-53557a7a5beb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateAcquiredThroughForeclosure_527c999c-378e-457a-be29-c6cffb69e862" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RealEstateAcquiredThroughForeclosure"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_RealEstateAcquiredThroughForeclosure_527c999c-378e-457a-be29-c6cffb69e862" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_5b6bf2ab-d926-46f1-8474-9ba974832f4e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_Goodwill_5b6bf2ab-d926-46f1-8474-9ba974832f4e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_bf8782b0-d3b9-45f8-bf17-d61e1f162bf8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_bf8782b0-d3b9-45f8-bf17-d61e1f162bf8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankOwnedLifeInsurance_7ae36980-ee2a-44e0-a361-5ad0236486d6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BankOwnedLifeInsurance"/>
    <link:calculationArc order="12" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_BankOwnedLifeInsurance_7ae36980-ee2a-44e0-a361-5ad0236486d6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssets_0f7e5fdd-6faa-4f1d-9884-d5dd295c49c6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherAssets"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_791b76d4-80a9-484c-b683-39ad3016bb9d" xlink:to="loc_us-gaap_OtherAssets_0f7e5fdd-6faa-4f1d-9884-d5dd295c49c6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_30e31f43-5e0a-4e30-a47d-be96c2d4fa68" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebt"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubordinatedDebt_f2e56de8-96da-4132-84b4-ae305553afac" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SubordinatedDebt"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_30e31f43-5e0a-4e30-a47d-be96c2d4fa68" xlink:to="loc_us-gaap_SubordinatedDebt_f2e56de8-96da-4132-84b4-ae305553afac" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLongTermDebt_5ec3f6b5-9dc4-454f-9a0f-ae6f43250d10" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherLongTermDebt"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_30e31f43-5e0a-4e30-a47d-be96c2d4fa68" xlink:to="loc_us-gaap_OtherLongTermDebt_5ec3f6b5-9dc4-454f-9a0f-ae6f43250d10" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalLeaseObligations_f5c99487-cc64-4b82-9bd3-b12ab38dbe90" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalLeaseObligations"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LongTermDebt_30e31f43-5e0a-4e30-a47d-be96c2d4fa68" xlink:to="loc_us-gaap_CapitalLeaseObligations_f5c99487-cc64-4b82-9bd3-b12ab38dbe90" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_fd93b9a6-da92-4579-b081-39aef0859fc0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_4bb4653a-6d88-4fbf-ba5f-3df073e70277" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_fd93b9a6-da92-4579-b081-39aef0859fc0" xlink:to="loc_us-gaap_PreferredStockValue_4bb4653a-6d88-4fbf-ba5f-3df073e70277" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_9984bd16-393e-45a1-9cd8-15c9ac35006b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_fd93b9a6-da92-4579-b081-39aef0859fc0" xlink:to="loc_us-gaap_CommonStockValue_9984bd16-393e-45a1-9cd8-15c9ac35006b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_d750f0ad-a890-41b0-92cf-2dd1926def77" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_fd93b9a6-da92-4579-b081-39aef0859fc0" xlink:to="loc_us-gaap_AdditionalPaidInCapital_d750f0ad-a890-41b0-92cf-2dd1926def77" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_0cddd504-757f-4d31-bde4-4ba5643e00ca" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_fd93b9a6-da92-4579-b081-39aef0859fc0" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_0cddd504-757f-4d31-bde4-4ba5643e00ca" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_9176d311-b011-4b7c-a0a0-e4f3b0dfbd6b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_fd93b9a6-da92-4579-b081-39aef0859fc0" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_9176d311-b011-4b7c-a0a0-e4f3b0dfbd6b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValue_ba20665d-24e9-4f6b-9377-a8bee296ab56" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockValue"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_fd93b9a6-da92-4579-b081-39aef0859fc0" xlink:to="loc_us-gaap_TreasuryStockValue_ba20665d-24e9-4f6b-9377-a8bee296ab56" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_68609f23-2912-4eae-8fbc-cac170119cfe" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_8c8c83ec-dca5-4774-8219-5415b1ae5e66" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Deposits"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_68609f23-2912-4eae-8fbc-cac170119cfe" xlink:to="loc_us-gaap_Deposits_8c8c83ec-dca5-4774-8219-5415b1ae5e66" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermBorrowings_8348850e-1ef0-4387-87e9-92de1d018f5b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShortTermBorrowings"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_68609f23-2912-4eae-8fbc-cac170119cfe" xlink:to="loc_us-gaap_ShortTermBorrowings_8348850e-1ef0-4387-87e9-92de1d018f5b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_de01d4f5-0f9d-442a-b54f-a877f09c6a81" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_68609f23-2912-4eae-8fbc-cac170119cfe" xlink:to="loc_us-gaap_LongTermDebt_de01d4f5-0f9d-442a-b54f-a877f09c6a81" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilities_9300f4d9-2897-4768-bad4-1863583ea276" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherLiabilities"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_68609f23-2912-4eae-8fbc-cac170119cfe" xlink:to="loc_us-gaap_OtherLiabilities_9300f4d9-2897-4768-bad4-1863583ea276" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_018d95cd-9acf-4936-8f6f-54bd479b130f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Deposits"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestBearingDepositLiabilitiesDomestic_e3ccdcbf-8153-48b1-b646-02adb2242587" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoninterestBearingDepositLiabilitiesDomestic"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_018d95cd-9acf-4936-8f6f-54bd479b130f" xlink:to="loc_us-gaap_NoninterestBearingDepositLiabilitiesDomestic_e3ccdcbf-8153-48b1-b646-02adb2242587" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositLiabilitiesDomestic_26bbfa5b-8e83-4f51-b717-5647b139ccfc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestBearingDepositLiabilitiesDomestic"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Deposits_018d95cd-9acf-4936-8f6f-54bd479b130f" xlink:to="loc_us-gaap_InterestBearingDepositLiabilitiesDomestic_26bbfa5b-8e83-4f51-b717-5647b139ccfc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableNetReportedAmount_466f7e09-6d5c-4b64-a01f-21e05d7f7401" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LoansAndLeasesReceivableNetReportedAmount"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome_048222f5-5f7c-4d8b-b1ac-5f688d6e0047" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LoansAndLeasesReceivableNetReportedAmount_466f7e09-6d5c-4b64-a01f-21e05d7f7401" xlink:to="loc_us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome_048222f5-5f7c-4d8b-b1ac-5f688d6e0047" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableAllowance_3c12eb77-c711-4c4b-95ee-3a061f8731f4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LoansAndLeasesReceivableAllowance"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LoansAndLeasesReceivableNetReportedAmount_466f7e09-6d5c-4b64-a01f-21e05d7f7401" xlink:to="loc_us-gaap_LoansAndLeasesReceivableAllowance_3c12eb77-c711-4c4b-95ee-3a061f8731f4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_669c69af-793e-4200-86b8-e464333ac525" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_47d44896-e111-49e4-a91c-9170769ef65c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_669c69af-793e-4200-86b8-e464333ac525" xlink:to="loc_us-gaap_Liabilities_47d44896-e111-49e4-a91c-9170769ef65c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_a54542fa-4d93-40f3-86c2-f003a0f80897" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_669c69af-793e-4200-86b8-e464333ac525" xlink:to="loc_us-gaap_StockholdersEquity_a54542fa-4d93-40f3-86c2-f003a0f80897" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofFinancialConditionUnauditedParenthetical" xlink:type="simple" xlink:href="fcf-20200331.xsd#CondensedConsolidatedStatementsofFinancialConditionUnauditedParenthetical"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofFinancialConditionUnauditedParenthetical" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofIncomeUnaudited" xlink:type="simple" xlink:href="fcf-20200331.xsd#CondensedConsolidatedStatementsofIncomeUnaudited"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofIncomeUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoninterestExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_339cde12-e5fc-497a-b5a8-285f020eb620" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_LaborAndRelatedExpense_339cde12-e5fc-497a-b5a8-285f020eb620" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OccupancyNet_618700bf-31f2-449b-b5a3-441c4a03a7d0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OccupancyNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_OccupancyNet_618700bf-31f2-449b-b5a3-441c4a03a7d0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquipmentExpense_27adbc47-6d93-4fb3-b84e-ca35703b53f2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquipmentExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_EquipmentExpense_27adbc47-6d93-4fb3-b84e-ca35703b53f2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InformationTechnologyAndDataProcessing_f0eeca31-2df6-4030-83a4-5ad887523ff2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InformationTechnologyAndDataProcessing"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_InformationTechnologyAndDataProcessing_f0eeca31-2df6-4030-83a4-5ad887523ff2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketingAndAdvertisingExpense_44d3f252-13aa-4a67-90d9-74ab08767229" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MarketingAndAdvertisingExpense"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_MarketingAndAdvertisingExpense_44d3f252-13aa-4a67-90d9-74ab08767229" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxesExcludingIncomeAndExciseTaxes_e19fca85-a8be-402a-a52f-80c390a677e0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxesExcludingIncomeAndExciseTaxes"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_TaxesExcludingIncomeAndExciseTaxes_e19fca85-a8be-402a-a52f-80c390a677e0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_060dd8be-e404-4c18-95a6-a83b854d1065" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_060dd8be-e404-4c18-95a6-a83b854d1065" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_CollectionAndRepossessionExpenses_5677651a-41c5-4be5-8a5b-b224fcc9f518" xlink:href="fcf-20200331.xsd#fcf_CollectionAndRepossessionExpenses"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_fcf_CollectionAndRepossessionExpenses_5677651a-41c5-4be5-8a5b-b224fcc9f518" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_745aa5cc-f114-4683-95bf-0e1118c5bbd1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProfessionalFees"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_ProfessionalFees_745aa5cc-f114-4683-95bf-0e1118c5bbd1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalDepositInsuranceCorporationPremiumExpense_cf6731cb-0fba-4ed2-b4a2-cd4d0f5441f5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FederalDepositInsuranceCorporationPremiumExpense"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_FederalDepositInsuranceCorporationPremiumExpense_cf6731cb-0fba-4ed2-b4a2-cd4d0f5441f5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges_9f4c9d26-24a3-49ad-96b0-4546f94d022a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges_9f4c9d26-24a3-49ad-96b0-4546f94d022a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_OperationalLoss_1806aae4-f3e6-4d69-b74a-d0b7f13f6ba7" xlink:href="fcf-20200331.xsd#fcf_OperationalLoss"/>
    <link:calculationArc order="12" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_fcf_OperationalLoss_1806aae4-f3e6-4d69-b74a-d0b7f13f6ba7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoninterestExpense_d223c7c8-06be-4963-9eef-8dbab686387e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNoninterestExpense"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_OtherNoninterestExpense_d223c7c8-06be-4963-9eef-8dbab686387e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OffBalanceSheetCreditLossLiabilityChangeInMethodCreditLossExpenseReversal_fb245559-160a-4142-adf7-ac1fee23d833" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OffBalanceSheetCreditLossLiabilityChangeInMethodCreditLossExpenseReversal"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_b7bedf22-b6c6-496d-b6a8-2ce776d7c863" xlink:to="loc_us-gaap_OffBalanceSheetCreditLossLiabilityChangeInMethodCreditLossExpenseReversal_fb245559-160a-4142-adf7-ac1fee23d833" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_11455d48-2424-4b29-85da-48b1d8c8322f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_e6b6683c-3b38-45e3-b781-03a4f0cd1185" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_11455d48-2424-4b29-85da-48b1d8c8322f" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_e6b6683c-3b38-45e3-b781-03a4f0cd1185" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_676d6b89-5cb3-4f64-a82d-94bcab6806cb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_11455d48-2424-4b29-85da-48b1d8c8322f" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_676d6b89-5cb3-4f64-a82d-94bcab6806cb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_0e9a949e-841a-4b51-afa1-b75f76dea0c3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases_6f262068-2bf7-46f8-8588-477afd894300" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestAndFeeIncomeLoansAndLeases"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_0e9a949e-841a-4b51-afa1-b75f76dea0c3" xlink:to="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases_6f262068-2bf7-46f8-8588-477afd894300" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesTaxable_1967e2bb-edf2-43de-9c01-d5a9261b68f7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestIncomeSecuritiesTaxable"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_0e9a949e-841a-4b51-afa1-b75f76dea0c3" xlink:to="loc_us-gaap_InterestIncomeSecuritiesTaxable_1967e2bb-edf2-43de-9c01-d5a9261b68f7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeSecuritiesTaxExempt_60137fe6-3a3a-4a18-90c1-04bc282e618f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestIncomeSecuritiesTaxExempt"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_0e9a949e-841a-4b51-afa1-b75f76dea0c3" xlink:to="loc_us-gaap_InterestIncomeSecuritiesTaxExempt_60137fe6-3a3a-4a18-90c1-04bc282e618f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendIncomeOperating_c2021229-e0b4-43eb-bb63-423f7821e512" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DividendIncomeOperating"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_0e9a949e-841a-4b51-afa1-b75f76dea0c3" xlink:to="loc_us-gaap_DividendIncomeOperating_c2021229-e0b4-43eb-bb63-423f7821e512" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeDepositsWithFinancialInstitutions_ce31e96d-83f6-4c0e-a35f-346d144ed610" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestIncomeDepositsWithFinancialInstitutions"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestAndDividendIncomeOperating_0e9a949e-841a-4b51-afa1-b75f76dea0c3" xlink:to="loc_us-gaap_InterestIncomeDepositsWithFinancialInstitutions_ce31e96d-83f6-4c0e-a35f-346d144ed610" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_a5c8d077-d493-43e8-bd50-c1d3560a631e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_c570d8e1-756b-4de4-9b81-15cab52fc114" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoninterestExpense"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_a5c8d077-d493-43e8-bd50-c1d3560a631e" xlink:to="loc_us-gaap_NoninterestExpense_c570d8e1-756b-4de4-9b81-15cab52fc114" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_d328719a-688e-4a14-a4a8-649492f41a19" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoninterestIncome"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_a5c8d077-d493-43e8-bd50-c1d3560a631e" xlink:to="loc_us-gaap_NoninterestIncome_d328719a-688e-4a14-a4a8-649492f41a19" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_7c202ed9-e051-41df-9255-31c04a7a702a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_a5c8d077-d493-43e8-bd50-c1d3560a631e" xlink:to="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_7c202ed9-e051-41df-9255-31c04a7a702a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoninterestIncome"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndEquitySecuritiesGainLoss_e4f511ef-3bab-45ce-ae60-f3513fa3c72a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtAndEquitySecuritiesGainLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:to="loc_us-gaap_DebtAndEquitySecuritiesGainLoss_e4f511ef-3bab-45ce-ae60-f3513fa3c72a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_FeesandCommissionsonTrustandFiduciaryAccounts_71d64594-c2be-4ed6-92ab-454c918bfaaf" xlink:href="fcf-20200331.xsd#fcf_FeesandCommissionsonTrustandFiduciaryAccounts"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:to="loc_fcf_FeesandCommissionsonTrustandFiduciaryAccounts_71d64594-c2be-4ed6-92ab-454c918bfaaf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_FeesandCommissionsonDepositorAccounts_081d0b68-3ab1-4c6e-b8db-6e0d37eeb6f5" xlink:href="fcf-20200331.xsd#fcf_FeesandCommissionsonDepositorAccounts"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:to="loc_fcf_FeesandCommissionsonDepositorAccounts_081d0b68-3ab1-4c6e-b8db-6e0d37eeb6f5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InsuranceCommissionsAndFees_f7b2b900-24ef-42a0-821b-94a3e1aa220f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InsuranceCommissionsAndFees"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:to="loc_us-gaap_InsuranceCommissionsAndFees_f7b2b900-24ef-42a0-821b-94a3e1aa220f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankOwnedLifeInsuranceIncome_c8244d38-dcf7-4ec3-affb-8283e38bfa7a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BankOwnedLifeInsuranceIncome"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:to="loc_us-gaap_BankOwnedLifeInsuranceIncome_c8244d38-dcf7-4ec3-affb-8283e38bfa7a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSalesOfLoansNet_9cf4cedc-a11e-48d4-8de4-a66a48a46448" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnSalesOfLoansNet"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:to="loc_us-gaap_GainLossOnSalesOfLoansNet_9cf4cedc-a11e-48d4-8de4-a66a48a46448" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets_0dd028b8-6bee-470b-aefa-4687cf9a0dfe" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GainLossOnDispositionOfAssets"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets_0dd028b8-6bee-470b-aefa-4687cf9a0dfe" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_FeesandCommissionsonDebitCards_b5e4feed-c33a-4efa-86b9-c6ae71bc52e5" xlink:href="fcf-20200331.xsd#fcf_FeesandCommissionsonDebitCards"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:to="loc_fcf_FeesandCommissionsonDebitCards_b5e4feed-c33a-4efa-86b9-c6ae71bc52e5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossOnDerivativeNet_faafcbe5-e166-4f48-b391-2fc36f9a6a4b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeGainLossOnDerivativeNet"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:to="loc_us-gaap_DerivativeGainLossOnDerivativeNet_faafcbe5-e166-4f48-b391-2fc36f9a6a4b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_DerivativeFeeIncome_28100526-c182-4212-96bf-075e3549531a" xlink:href="fcf-20200331.xsd#fcf_DerivativeFeeIncome"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:to="loc_fcf_DerivativeFeeIncome_28100526-c182-4212-96bf-075e3549531a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncomeOtherOperatingIncome_b4c00758-6112-45bb-92d2-ac9020c7a02c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoninterestIncomeOtherOperatingIncome"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestIncome_f2be7746-0a97-434f-9354-985807d43df6" xlink:to="loc_us-gaap_NoninterestIncomeOtherOperatingIncome_b4c00758-6112-45bb-92d2-ac9020c7a02c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_b017d9eb-5611-4bf0-915b-cbccfbe2548d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_842cc7d9-7237-49b5-9aa7-120eb01f3947" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseNet_b017d9eb-5611-4bf0-915b-cbccfbe2548d" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperating_842cc7d9-7237-49b5-9aa7-120eb01f3947" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_f934eef0-5a2d-44b3-b5df-bef27a4ce86e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpense"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseNet_b017d9eb-5611-4bf0-915b-cbccfbe2548d" xlink:to="loc_us-gaap_InterestExpense_f934eef0-5a2d-44b3-b5df-bef27a4ce86e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_0c2ee44f-1d4c-4caa-b446-17bcc6ace854" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDeposits_ce4851ba-390b-4d6c-8486-2de54cd4513e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpenseDeposits"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_0c2ee44f-1d4c-4caa-b446-17bcc6ace854" xlink:to="loc_us-gaap_InterestExpenseDeposits_ce4851ba-390b-4d6c-8486-2de54cd4513e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseShortTermBorrowings_5efe1fb6-1b62-4eeb-8774-cdadbf890b1e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpenseShortTermBorrowings"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_0c2ee44f-1d4c-4caa-b446-17bcc6ace854" xlink:to="loc_us-gaap_InterestExpenseShortTermBorrowings_5efe1fb6-1b62-4eeb-8774-cdadbf890b1e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseSubordinatedNotesAndDebentures_f18e9dea-8111-45c9-8e04-2725736496be" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpenseSubordinatedNotesAndDebentures"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_0c2ee44f-1d4c-4caa-b446-17bcc6ace854" xlink:to="loc_us-gaap_InterestExpenseSubordinatedNotesAndDebentures_f18e9dea-8111-45c9-8e04-2725736496be" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOtherLongTermDebt_8d273350-39c5-4c04-b49f-45be491680c4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpenseOtherLongTermDebt"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_0c2ee44f-1d4c-4caa-b446-17bcc6ace854" xlink:to="loc_us-gaap_InterestExpenseOtherLongTermDebt_8d273350-39c5-4c04-b49f-45be491680c4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseLesseeAssetsUnderCapitalLease_38092399-3d56-431e-8d84-bfad82768a41" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpenseLesseeAssetsUnderCapitalLease"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestExpense_0c2ee44f-1d4c-4caa-b446-17bcc6ace854" xlink:to="loc_us-gaap_InterestExpenseLesseeAssetsUnderCapitalLease_38092399-3d56-431e-8d84-bfad82768a41" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_07165f73-1449-4f2f-bc0b-e891a7179726" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_7d9932de-3a31-4196-9eb9-2b7f40dd5faa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_07165f73-1449-4f2f-bc0b-e891a7179726" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_7d9932de-3a31-4196-9eb9-2b7f40dd5faa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanAndLeaseLosses_53db8427-a60d-4d3a-9b15-c6421bcb004d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProvisionForLoanAndLeaseLosses"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_07165f73-1449-4f2f-bc0b-e891a7179726" xlink:to="loc_us-gaap_ProvisionForLoanAndLeaseLosses_53db8427-a60d-4d3a-9b15-c6421bcb004d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofComprehensiveIncomeUnaudited" xlink:type="simple" xlink:href="fcf-20200331.xsd#CondensedConsolidatedStatementsofComprehensiveIncomeUnaudited"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofComprehensiveIncomeUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_9bb6812f-e38e-48b2-b13d-cf583be435b6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_79d46db3-be1a-40c3-aa3c-e0357b8e5520" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_9bb6812f-e38e-48b2-b13d-cf583be435b6" xlink:to="loc_us-gaap_NetIncomeLoss_79d46db3-be1a-40c3-aa3c-e0357b8e5520" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_e88970ff-e202-45ea-ae81-c05783c52b25" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_9bb6812f-e38e-48b2-b13d-cf583be435b6" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_e88970ff-e202-45ea-ae81-c05783c52b25" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent_45b44dd7-7008-4752-88f7-f4692ab007e0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_e7be0e8a-3ea4-4909-8602-b0db3339bb0b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent_45b44dd7-7008-4752-88f7-f4692ab007e0" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_e7be0e8a-3ea4-4909-8602-b0db3339bb0b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax_178a0453-e65f-443e-a3ac-2024cef1fa4e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent_45b44dd7-7008-4752-88f7-f4692ab007e0" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax_178a0453-e65f-443e-a3ac-2024cef1fa4e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax_17983fe9-72d2-4fc7-91f8-ca7e67cf3a9a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent_45b44dd7-7008-4752-88f7-f4692ab007e0" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax_17983fe9-72d2-4fc7-91f8-ca7e67cf3a9a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax_43fb82b0-02fd-48d7-95d7-04ce68116d12" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent_45b44dd7-7008-4752-88f7-f4692ab007e0" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax_43fb82b0-02fd-48d7-95d7-04ce68116d12" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_24e4a4b2-74bd-48a3-a90f-d4793f9a2540" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent_01ba8ce3-f062-4874-be42-1a12e9cd1c32" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_24e4a4b2-74bd-48a3-a90f-d4793f9a2540" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent_01ba8ce3-f062-4874-be42-1a12e9cd1c32" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1_5694cc12-1412-4d02-8bff-00117c36d911" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_24e4a4b2-74bd-48a3-a90f-d4793f9a2540" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1_5694cc12-1412-4d02-8bff-00117c36d911" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofChangesinShareholdersEquityUnaudited" xlink:type="simple" xlink:href="fcf-20200331.xsd#CondensedConsolidatedStatementsofChangesinShareholdersEquityUnaudited"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofChangesinShareholdersEquityUnaudited" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofChangesinShareholdersEquityUnauditedParenthetical" xlink:type="simple" xlink:href="fcf-20200331.xsd#CondensedConsolidatedStatementsofChangesinShareholdersEquityUnauditedParenthetical"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofChangesinShareholdersEquityUnauditedParenthetical" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofCashFlowsUnaudited" xlink:type="simple" xlink:href="fcf-20200331.xsd#CondensedConsolidatedStatementsofCashFlowsUnaudited"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofCashFlowsUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfHeldToMaturitySecurities_8040be8c-fa74-4315-9be7-7e6c25bb87a2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfHeldToMaturitySecurities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfHeldToMaturitySecurities_8040be8c-fa74-4315-9be7-7e6c25bb87a2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities_ed22965d-6294-4f18-a7ac-e6bc5c55e671" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:to="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities_ed22965d-6294-4f18-a7ac-e6bc5c55e671" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_157e8d0b-7d4b-43e5-bfcc-0735a19c3653" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_157e8d0b-7d4b-43e5-bfcc-0735a19c3653" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromFederalHomeLoanBankStock_4956ed5d-7014-450c-b2a2-5afbb0abfbe7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForProceedsFromFederalHomeLoanBankStock"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:to="loc_us-gaap_PaymentsForProceedsFromFederalHomeLoanBankStock_4956ed5d-7014-450c-b2a2-5afbb0abfbe7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfFederalHomeLoanBankStock_6e392cf3-5044-4bd3-9baf-be49867444d9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromSaleOfFederalHomeLoanBankStock"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:to="loc_us-gaap_ProceedsFromSaleOfFederalHomeLoanBankStock_6e392cf3-5044-4bd3-9baf-be49867444d9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromLifeInsurancePolicies_cdb12969-581e-40f5-8260-354eba6b5aaf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromLifeInsurancePolicies"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:to="loc_us-gaap_ProceedsFromLifeInsurancePolicies_cdb12969-581e-40f5-8260-354eba6b5aaf" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfLoansReceivable_81c20a65-81e4-4b3c-b279-127018a1b9c5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromSaleOfLoansReceivable"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:to="loc_us-gaap_ProceedsFromSaleOfLoansReceivable_81c20a65-81e4-4b3c-b279-127018a1b9c5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfOtherProductiveAssets_ee141ec9-3bfe-45b3-988f-7dff8104e6f9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromSaleOfOtherProductiveAssets"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:to="loc_us-gaap_ProceedsFromSaleOfOtherProductiveAssets_ee141ec9-3bfe-45b3-988f-7dff8104e6f9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromLoansAndLeases_245054a8-2f42-4826-b14a-583e9013ff00" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForProceedsFromLoansAndLeases"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:to="loc_us-gaap_PaymentsForProceedsFromLoansAndLeases_245054a8-2f42-4826-b14a-583e9013ff00" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForPurchaseOfOtherAssets1_a74475db-5ba0-420a-ab7a-e34865099950" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForPurchaseOfOtherAssets1"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:to="loc_us-gaap_PaymentsForPurchaseOfOtherAssets1_a74475db-5ba0-420a-ab7a-e34865099950" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecurities_3bc6bc4d-31ff-4789-b92a-0d7d2a791dfc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecurities"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_c916803d-8bcb-4177-9c01-406978587ae6" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecurities_3bc6bc4d-31ff-4789-b92a-0d7d2a791dfc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_0b34cb93-03c6-4dc6-bf78-70e4fdb4f206" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInFederalFundsPurchased_86e55cb6-d6d5-47fa-838d-4d4262fdfd8c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInFederalFundsPurchased"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_0b34cb93-03c6-4dc6-bf78-70e4fdb4f206" xlink:to="loc_us-gaap_IncreaseDecreaseInFederalFundsPurchased_86e55cb6-d6d5-47fa-838d-4d4262fdfd8c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromRepaymentsOfShortTermDebt_9f3edaca-b550-4d68-b7e4-d41e1208be56" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromRepaymentsOfShortTermDebt"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_0b34cb93-03c6-4dc6-bf78-70e4fdb4f206" xlink:to="loc_us-gaap_ProceedsFromRepaymentsOfShortTermDebt_9f3edaca-b550-4d68-b7e4-d41e1208be56" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInDeposits_96dd9f90-8510-4422-ae9b-ae931eb820bc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInDeposits"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_0b34cb93-03c6-4dc6-bf78-70e4fdb4f206" xlink:to="loc_us-gaap_IncreaseDecreaseInDeposits_96dd9f90-8510-4422-ae9b-ae931eb820bc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfOtherLongTermDebt_2dcd8ec5-b913-4fdc-aeab-209c57457926" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RepaymentsOfOtherLongTermDebt"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_0b34cb93-03c6-4dc6-bf78-70e4fdb4f206" xlink:to="loc_us-gaap_RepaymentsOfOtherLongTermDebt_2dcd8ec5-b913-4fdc-aeab-209c57457926" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLongTermCapitalLeaseObligations_e3f5d01d-4811-4aa7-a3ac-82be6e7473b3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RepaymentsOfLongTermCapitalLeaseObligations"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_0b34cb93-03c6-4dc6-bf78-70e4fdb4f206" xlink:to="loc_us-gaap_RepaymentsOfLongTermCapitalLeaseObligations_e3f5d01d-4811-4aa7-a3ac-82be6e7473b3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividends_bb1713c9-0ae1-48c0-9ca3-b8e163ed4de3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsOfDividends"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_0b34cb93-03c6-4dc6-bf78-70e4fdb4f206" xlink:to="loc_us-gaap_PaymentsOfDividends_bb1713c9-0ae1-48c0-9ca3-b8e163ed4de3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_1df7c5c7-5185-4ff7-84ee-0f23d572b955" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_0b34cb93-03c6-4dc6-bf78-70e4fdb4f206" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_1df7c5c7-5185-4ff7-84ee-0f23d572b955" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_859e555e-ec6b-48fe-b9f4-75fb09dd46a8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_us-gaap_NetIncomeLoss_859e555e-ec6b-48fe-b9f4-75fb09dd46a8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanAndLeaseLosses_4886cd04-d732-4535-a60d-ac1b5fea2d97" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProvisionForLoanAndLeaseLosses"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_us-gaap_ProvisionForLoanAndLeaseLosses_4886cd04-d732-4535-a60d-ac1b5fea2d97" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_de2ad8eb-8ab9-4c04-9fca-eeaf31dc1f89" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_de2ad8eb-8ab9-4c04-9fca-eeaf31dc1f89" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAmortizationAndAccretionNet_9ca97926-b702-43de-9e43-36e1525b2296" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DepreciationAmortizationAndAccretionNet"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_us-gaap_DepreciationAmortizationAndAccretionNet_9ca97926-b702-43de-9e43-36e1525b2296" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_GainLossOnSecuritiesAndOtherAssets_063cf34a-e89b-4ac8-9e26-87a682ff72f0" xlink:href="fcf-20200331.xsd#fcf_GainLossOnSecuritiesAndOtherAssets"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_fcf_GainLossOnSecuritiesAndOtherAssets_063cf34a-e89b-4ac8-9e26-87a682ff72f0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_e7f7b787-fdc3-4054-b3c5-4555212a8846" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_e7f7b787-fdc3-4054-b3c5-4555212a8846" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_IncreaseInCashSurrenderValueofBOLI_4e26094c-acd1-48d6-9c32-980e021be420" xlink:href="fcf-20200331.xsd#fcf_IncreaseInCashSurrenderValueofBOLI"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_fcf_IncreaseInCashSurrenderValueofBOLI_4e26094c-acd1-48d6-9c32-980e021be420" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet_3554c0e4-e95a-4ccb-a02b-bfb4837989b1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet_3554c0e4-e95a-4ccb-a02b-bfb4837989b1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForOriginationOfMortgageLoansHeldForSale_eec8afd7-f590-4dc3-92e2-764c42c9d9ab" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForOriginationOfMortgageLoansHeldForSale"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_us-gaap_PaymentsForOriginationOfMortgageLoansHeldForSale_eec8afd7-f590-4dc3-92e2-764c42c9d9ab" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInterestPayableNet_4dbffdcd-ee42-438d-a51b-662cc9473db7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInInterestPayableNet"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_us-gaap_IncreaseDecreaseInInterestPayableNet_4dbffdcd-ee42-438d-a51b-662cc9473db7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_cda57200-1f1d-4b5f-b938-afaada9a61f8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_cda57200-1f1d-4b5f-b938-afaada9a61f8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_f0e09576-6079-4314-ba47-1e1ed740e5f6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet"/>
    <link:calculationArc order="12" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_f0e09576-6079-4314-ba47-1e1ed740e5f6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale_8530fed4-c34d-4fe3-8ac6-4027ed2f915f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_9b034bc2-8860-42b5-97c5-521e43131325" xlink:to="loc_us-gaap_ProceedsFromSaleOfMortgageLoansHeldForSale_8530fed4-c34d-4fe3-8ac6-4027ed2f915f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_8d97c523-1a84-4c4c-928c-4093197c0e5b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_33824362-dee4-4045-82c1-6ec88b705b48" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_8d97c523-1a84-4c4c-928c-4093197c0e5b" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_33824362-dee4-4045-82c1-6ec88b705b48" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_fe8d9c82-91b3-4b08-9b9f-0b2e13267d13" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_8d97c523-1a84-4c4c-928c-4093197c0e5b" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_fe8d9c82-91b3-4b08-9b9f-0b2e13267d13" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_48152af0-ef84-4dd1-90dc-dde640388cc4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_8d97c523-1a84-4c4c-928c-4093197c0e5b" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_48152af0-ef84-4dd1-90dc-dde640388cc4" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/BasisofPresentation" xlink:type="simple" xlink:href="fcf-20200331.xsd#BasisofPresentation"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/BasisofPresentation" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/SupplementalComprehensiveIncomeDisclosures" xlink:type="simple" xlink:href="fcf-20200331.xsd#SupplementalComprehensiveIncomeDisclosures"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/SupplementalComprehensiveIncomeDisclosures" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/SupplementalComprehensiveIncomeDisclosures_1" xlink:type="simple" xlink:href="fcf-20200331.xsd#SupplementalComprehensiveIncomeDisclosures_1"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/SupplementalComprehensiveIncomeDisclosures_1" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/SupplementalComprehensiveIncomeDisclosures_2" xlink:type="simple" xlink:href="fcf-20200331.xsd#SupplementalComprehensiveIncomeDisclosures_2"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/SupplementalComprehensiveIncomeDisclosures_2" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax_c8bdcacf-3958-460e-ab18-9b98d0acd510" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_55ac34a7-2493-48d4-8ff7-82743dc3544b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax_c8bdcacf-3958-460e-ab18-9b98d0acd510" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax_55ac34a7-2493-48d4-8ff7-82743dc3544b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax_4637d278-55a1-4eb4-aa33-405cb16b3087" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax_c8bdcacf-3958-460e-ab18-9b98d0acd510" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax_4637d278-55a1-4eb4-aa33-405cb16b3087" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_ca4c3adc-a0f3-4d49-a956-341be36b5a19" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_42e7874a-64d1-41b8-a731-ecd09946f0c6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_ca4c3adc-a0f3-4d49-a956-341be36b5a19" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_42e7874a-64d1-41b8-a731-ecd09946f0c6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_6fec30af-e080-45e8-b673-eb3515f13797" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_ca4c3adc-a0f3-4d49-a956-341be36b5a19" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_6fec30af-e080-45e8-b673-eb3515f13797" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax_e58aa521-ef23-40a7-b056-97cec6a34b28" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_8b623600-50c4-49aa-ab20-66a270b9e873" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax_e58aa521-ef23-40a7-b056-97cec6a34b28" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_8b623600-50c4-49aa-ab20-66a270b9e873" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax_a5521633-715b-4759-8253-a0e1d935601b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax_e58aa521-ef23-40a7-b056-97cec6a34b28" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax_a5521633-715b-4759-8253-a0e1d935601b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTax_e8212f94-ae0f-44b3-9b76-c87330befa14" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_50305110-225b-4bcf-a9cf-7873426cc21b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossTax_e8212f94-ae0f-44b3-9b76-c87330befa14" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax_50305110-225b-4bcf-a9cf-7873426cc21b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax_fe27c301-03f9-40aa-89be-0f1566f0c3fc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossTax_e8212f94-ae0f-44b3-9b76-c87330befa14" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax_fe27c301-03f9-40aa-89be-0f1566f0c3fc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax_4526ae57-b18c-4921-939b-17f96f67b8eb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossTax_e8212f94-ae0f-44b3-9b76-c87330befa14" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax_4526ae57-b18c-4921-939b-17f96f67b8eb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax_3f95ca0e-b57d-44cc-9e24-7df0b26666a1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossTax_e8212f94-ae0f-44b3-9b76-c87330befa14" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax_3f95ca0e-b57d-44cc-9e24-7df0b26666a1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax_c9021041-0551-4089-b75d-ef16c2483fee" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax_3495f1b1-c3de-44df-92d4-79eb82772bc5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax_c9021041-0551-4089-b75d-ef16c2483fee" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax_3495f1b1-c3de-44df-92d4-79eb82772bc5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax_af0476b7-1023-4a9e-8d57-17c7f2b7b1f0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax_c9021041-0551-4089-b75d-ef16c2483fee" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax_af0476b7-1023-4a9e-8d57-17c7f2b7b1f0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax_1a7af59f-722c-4d41-a847-2b672047e857" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_3bafdc2e-94f5-47ad-add5-256322aa718b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax_1a7af59f-722c-4d41-a847-2b672047e857" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_3bafdc2e-94f5-47ad-add5-256322aa718b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax_883ee5a1-b66b-4c8a-870a-9d0e459af00b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax_1a7af59f-722c-4d41-a847-2b672047e857" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax_883ee5a1-b66b-4c8a-870a-9d0e459af00b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_b37d7ca6-cc52-406d-ad51-2c1aed2c5c92" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_83c6e08a-bb73-48bc-b448-f200d2d913a1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_b37d7ca6-cc52-406d-ad51-2c1aed2c5c92" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax_83c6e08a-bb73-48bc-b448-f200d2d913a1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax_fc2b06ce-a76e-4bc3-becf-14549e7e1f34" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_b37d7ca6-cc52-406d-ad51-2c1aed2c5c92" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax_fc2b06ce-a76e-4bc3-becf-14549e7e1f34" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax_a5fa24a2-97ac-4801-a387-cce70737c4ad" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_b37d7ca6-cc52-406d-ad51-2c1aed2c5c92" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax_a5fa24a2-97ac-4801-a387-cce70737c4ad" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax_c27b361b-7424-4920-8fa3-d205a2872909" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossBeforeTax_b37d7ca6-cc52-406d-ad51-2c1aed2c5c92" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax_c27b361b-7424-4920-8fa3-d205a2872909" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax_0dff5ea6-0733-4bcf-89a0-c4acc07d2924" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax_676167c2-6c11-482d-9ff1-77ae5ffb0c5d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax_0dff5ea6-0733-4bcf-89a0-c4acc07d2924" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax_676167c2-6c11-482d-9ff1-77ae5ffb0c5d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax_08f8e85f-4e92-40f4-8052-83ddf4abeb48" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax_0dff5ea6-0733-4bcf-89a0-c4acc07d2924" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax_08f8e85f-4e92-40f4-8052-83ddf4abeb48" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/SupplementalComprehensiveIncomeDisclosures_3" xlink:type="simple" xlink:href="fcf-20200331.xsd#SupplementalComprehensiveIncomeDisclosures_3"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/SupplementalComprehensiveIncomeDisclosures_3" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_79e8217c-391c-4de0-b316-ccb50271eaac" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_09b3460d-27f4-41af-bb8e-95d957ae3635" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_79e8217c-391c-4de0-b316-ccb50271eaac" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_09b3460d-27f4-41af-bb8e-95d957ae3635" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_fb9ed77e-d585-44d9-8e0a-b2ecfcd7c9ad" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_79e8217c-391c-4de0-b316-ccb50271eaac" xlink:to="loc_us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax_fb9ed77e-d585-44d9-8e0a-b2ecfcd7c9ad" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/SupplementalCashFlowDisclosures" xlink:type="simple" xlink:href="fcf-20200331.xsd#SupplementalCashFlowDisclosures"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/SupplementalCashFlowDisclosures" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/SupplementalCashFlowDisclosures_1" xlink:type="simple" xlink:href="fcf-20200331.xsd#SupplementalCashFlowDisclosures_1"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/SupplementalCashFlowDisclosures_1" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/SupplementalCashFlowDisclosuresNoncashInvestingandFinancingActivities" xlink:type="simple" xlink:href="fcf-20200331.xsd#SupplementalCashFlowDisclosuresNoncashInvestingandFinancingActivities"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/SupplementalCashFlowDisclosuresNoncashInvestingandFinancingActivities" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/EarningsperShare" xlink:type="simple" xlink:href="fcf-20200331.xsd#EarningsperShare"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/EarningsperShare" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/EarningsperShareTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#EarningsperShareTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/EarningsperShareTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/EarningsperShareCompositionofWeightedAverageCommonSharesDenominatorUsedinBasicandDilutedEarningsPerShareDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#EarningsperShareCompositionofWeightedAverageCommonSharesDenominatorUsedinBasicandDilutedEarningsPerShareDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/EarningsperShareCompositionofWeightedAverageCommonSharesDenominatorUsedinBasicandDilutedEarningsPerShareDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_2efc271c-122a-44f4-a682-5a53e9120a78" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesIssuedBasic_f7302042-5bd9-4ec0-8ebb-7da5ce8c2455" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesIssuedBasic"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_2efc271c-122a-44f4-a682-5a53e9120a78" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesIssuedBasic_f7302042-5bd9-4ec0-8ebb-7da5ce8c2455" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesTreasuryStock_2483d9ba-fad9-476c-9c2b-746d7be38e1f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesTreasuryStock"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_2efc271c-122a-44f4-a682-5a53e9120a78" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesTreasuryStock_2483d9ba-fad9-476c-9c2b-746d7be38e1f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_WeightedAverageNumberofSharesDeferredCompensationPlans_81ebecaf-1d24-4df6-bcfb-aeda582b5e52" xlink:href="fcf-20200331.xsd#fcf_WeightedAverageNumberofSharesDeferredCompensationPlans"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_2efc271c-122a-44f4-a682-5a53e9120a78" xlink:to="loc_fcf_WeightedAverageNumberofSharesDeferredCompensationPlans_81ebecaf-1d24-4df6-bcfb-aeda582b5e52" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesRestrictedStock_13801231-c695-403c-97b2-48c238ea1e9a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesRestrictedStock"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_2efc271c-122a-44f4-a682-5a53e9120a78" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesRestrictedStock_13801231-c695-403c-97b2-48c238ea1e9a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_dfc8feb8-2af2-4880-b154-1357091c606d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_7b926a5a-6a18-445f-a4aa-9f7a4b975d5b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_dfc8feb8-2af2-4880-b154-1357091c606d" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_7b926a5a-6a18-445f-a4aa-9f7a4b975d5b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToParticipatingNonvestedSharesWithNonForfeitableDividendRights_7d810ec8-7187-4aa3-930d-b481e9442f0a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToParticipatingNonvestedSharesWithNonForfeitableDividendRights"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_dfc8feb8-2af2-4880-b154-1357091c606d" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToParticipatingNonvestedSharesWithNonForfeitableDividendRights_7d810ec8-7187-4aa3-930d-b481e9442f0a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_WeightedAverageNumberOfAdditionalSharesDeferredCompensationPlan_38e81f81-8898-42e1-bc05-04a6f256493d" xlink:href="fcf-20200331.xsd#fcf_WeightedAverageNumberOfAdditionalSharesDeferredCompensationPlan"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_dfc8feb8-2af2-4880-b154-1357091c606d" xlink:to="loc_fcf_WeightedAverageNumberOfAdditionalSharesDeferredCompensationPlan_38e81f81-8898-42e1-bc05-04a6f256493d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/EarningsperShareCommonStockEquivalentsNotIncludedinComputationofDilutedEarningsPerShareDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#EarningsperShareCommonStockEquivalentsNotIncludedinComputationofDilutedEarningsPerShareDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/EarningsperShareCommonStockEquivalentsNotIncludedinComputationofDilutedEarningsPerShareDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/CommitmentsandContingentLiabilities" xlink:type="simple" xlink:href="fcf-20200331.xsd#CommitmentsandContingentLiabilities"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CommitmentsandContingentLiabilities" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/CommitmentsandContingentLiabilitiesTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#CommitmentsandContingentLiabilitiesTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CommitmentsandContingentLiabilitiesTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/CommitmentsandContingentLiabilitiesNotionalAmountofOutstandingCommitmentsDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#CommitmentsandContingentLiabilitiesNotionalAmountofOutstandingCommitmentsDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CommitmentsandContingentLiabilitiesNotionalAmountofOutstandingCommitmentsDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/CommitmentsandContingentLiabilitiesAdditionalInformationDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#CommitmentsandContingentLiabilitiesAdditionalInformationDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/CommitmentsandContingentLiabilitiesAdditionalInformationDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/InvestmentSecurities" xlink:type="simple" xlink:href="fcf-20200331.xsd#InvestmentSecurities"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/InvestmentSecurities" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#InvestmentSecuritiesTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/InvestmentSecuritiesTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesMaturityofHeldtoMaturitySecuritiesTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#InvestmentSecuritiesMaturityofHeldtoMaturitySecuritiesTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/InvestmentSecuritiesMaturityofHeldtoMaturitySecuritiesTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesAnalysisofAmortizedCostandEstimatedFairValuesofSecuritiesAvailableforSaleDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#InvestmentSecuritiesAnalysisofAmortizedCostandEstimatedFairValuesofSecuritiesAvailableforSaleDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/InvestmentSecuritiesAnalysisofAmortizedCostandEstimatedFairValuesofSecuritiesAvailableforSaleDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesAmortizedCostandEstimatedFairValueofDebtSecuritiesAvailableforSaleDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#InvestmentSecuritiesAmortizedCostandEstimatedFairValueofDebtSecuritiesAvailableforSaleDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/InvestmentSecuritiesAmortizedCostandEstimatedFairValueofDebtSecuritiesAvailableforSaleDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesAmortizedCostandEstimatedFairValueofDebtSecuritiesAvailableforSaleDetail1" xlink:type="simple" xlink:href="fcf-20200331.xsd#InvestmentSecuritiesAmortizedCostandEstimatedFairValueofDebtSecuritiesAvailableforSaleDetail1"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/InvestmentSecuritiesAmortizedCostandEstimatedFairValueofDebtSecuritiesAvailableforSaleDetail1" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesProceedsfromSaleGrossGainsLossesRealizedonSalesMaturitiesandOtherThanTemporaryImpairmentChargesRelatedtoSecuritiesAvailableforSaleDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#InvestmentSecuritiesProceedsfromSaleGrossGainsLossesRealizedonSalesMaturitiesandOtherThanTemporaryImpairmentChargesRelatedtoSecuritiesAvailableforSaleDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/InvestmentSecuritiesProceedsfromSaleGrossGainsLossesRealizedonSalesMaturitiesandOtherThanTemporaryImpairmentChargesRelatedtoSecuritiesAvailableforSaleDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_fcf_NetGainsAndImpairment_b176b642-29b0-4c2c-9cb9-f205802c1c2a" xlink:href="fcf-20200331.xsd#fcf_NetGainsAndImpairment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedGains_59f26d4c-7671-4ff1-9606-9065c1d5a316" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossRealizedGains"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_fcf_NetGainsAndImpairment_b176b642-29b0-4c2c-9cb9-f205802c1c2a" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedGains_59f26d4c-7671-4ff1-9606-9065c1d5a316" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses_87a2df33-1eb6-4d05-b411-5df92873f8e5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_fcf_NetGainsAndImpairment_b176b642-29b0-4c2c-9cb9-f205802c1c2a" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses_87a2df33-1eb6-4d05-b411-5df92873f8e5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_GrossGains_0c0131e1-c121-457c-b156-cadc9be94da5" xlink:href="fcf-20200331.xsd#fcf_GrossGains"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_fcf_NetGainsAndImpairment_b176b642-29b0-4c2c-9cb9-f205802c1c2a" xlink:to="loc_fcf_GrossGains_0c0131e1-c121-457c-b156-cadc9be94da5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_GrossLosses_ead445a5-d8da-497d-af2f-d222509a7ba0" xlink:href="fcf-20200331.xsd#fcf_GrossLosses"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_fcf_NetGainsAndImpairment_b176b642-29b0-4c2c-9cb9-f205802c1c2a" xlink:to="loc_fcf_GrossLosses_ead445a5-d8da-497d-af2f-d222509a7ba0" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesAdditionalInformationDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#InvestmentSecuritiesAdditionalInformationDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/InvestmentSecuritiesAdditionalInformationDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesScheduleofHeldtoMaturitySecuritiesDetails" xlink:type="simple" xlink:href="fcf-20200331.xsd#InvestmentSecuritiesScheduleofHeldtoMaturitySecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/InvestmentSecuritiesScheduleofHeldtoMaturitySecuritiesDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesHeldtoMaturitySecuritiesbyTypeDetails" xlink:type="simple" xlink:href="fcf-20200331.xsd#InvestmentSecuritiesHeldtoMaturitySecuritiesbyTypeDetails"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/InvestmentSecuritiesHeldtoMaturitySecuritiesbyTypeDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/OtherInvestments" xlink:type="simple" xlink:href="fcf-20200331.xsd#OtherInvestments"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/OtherInvestments" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/OtherInvestmentsAdditionalInformation" xlink:type="simple" xlink:href="fcf-20200331.xsd#OtherInvestmentsAdditionalInformation"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/OtherInvestmentsAdditionalInformation" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/ImpairmentofInvestmentSecurities" xlink:type="simple" xlink:href="fcf-20200331.xsd#ImpairmentofInvestmentSecurities"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/ImpairmentofInvestmentSecurities" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/ImpairmentofInvestmentSecuritiesTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#ImpairmentofInvestmentSecuritiesTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/ImpairmentofInvestmentSecuritiesTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/ImpairmentofInvestmentSecuritiesAdditionalInformationDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#ImpairmentofInvestmentSecuritiesAdditionalInformationDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/ImpairmentofInvestmentSecuritiesAdditionalInformationDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/ImpairmentofInvestmentSecuritiesScheduleofUnrealizedLossesandEstimatedFairValuesDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#ImpairmentofInvestmentSecuritiesScheduleofUnrealizedLossesandEstimatedFairValuesDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/ImpairmentofInvestmentSecuritiesScheduleofUnrealizedLossesandEstimatedFairValuesDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_fe4aba04-8ae7-450f-9817-98df5d7a7f4a" xlink:href="fcf-20200331.xsd#fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPosition12MonthsorLongerAccumulatedLoss_5097fd1c-691c-4979-af57-3c69ac2b71f8" xlink:href="fcf-20200331.xsd#fcf_InvestmentSecuritiesContinuousUnrealizedLossPosition12MonthsorLongerAccumulatedLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_fe4aba04-8ae7-450f-9817-98df5d7a7f4a" xlink:to="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPosition12MonthsorLongerAccumulatedLoss_5097fd1c-691c-4979-af57-3c69ac2b71f8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionLessthan12MonthsAccumulatedLoss_97bb14ff-de4f-45e7-a64f-e6ce5c9ec1f6" xlink:href="fcf-20200331.xsd#fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionLessthan12MonthsAccumulatedLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss_fe4aba04-8ae7-450f-9817-98df5d7a7f4a" xlink:to="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionLessthan12MonthsAccumulatedLoss_97bb14ff-de4f-45e7-a64f-e6ce5c9ec1f6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionFairValueTotal_a4e60223-7513-44d1-9b68-966aa782ae38" xlink:href="fcf-20200331.xsd#fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionFairValueTotal"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionLessthanTwelveMonthsFairValue_707000cf-edd8-4f75-b77d-f2ec1ba47663" xlink:href="fcf-20200331.xsd#fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionLessthanTwelveMonthsFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionFairValueTotal_a4e60223-7513-44d1-9b68-966aa782ae38" xlink:to="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionLessthanTwelveMonthsFairValue_707000cf-edd8-4f75-b77d-f2ec1ba47663" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionTwelveMonthsorLongerFairValue_1478d716-d9ba-469c-ac3c-9c323123b465" xlink:href="fcf-20200331.xsd#fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionTwelveMonthsorLongerFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionFairValueTotal_a4e60223-7513-44d1-9b68-966aa782ae38" xlink:to="loc_fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionTwelveMonthsorLongerFairValue_1478d716-d9ba-469c-ac3c-9c323123b465" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLosses" xlink:type="simple" xlink:href="fcf-20200331.xsd#LoansandAllowanceforCreditLosses"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LoansandAllowanceforCreditLosses" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#LoansandAllowanceforCreditLossesTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesOutstandingBalancesofLoanDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#LoansandAllowanceforCreditLossesOutstandingBalancesofLoanDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesOutstandingBalancesofLoanDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesAdditionalInformationDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#LoansandAllowanceforCreditLossesAdditionalInformationDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesAdditionalInformationDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesCreditRiskProfilebyCreditworthinessDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#LoansandAllowanceforCreditLossesCreditRiskProfilebyCreditworthinessDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesCreditRiskProfilebyCreditworthinessDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesAgeAnalysisofPastDueLoansbySegmentDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#LoansandAllowanceforCreditLossesAgeAnalysisofPastDueLoansbySegmentDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesAgeAnalysisofPastDueLoansbySegmentDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome_f4f8d61c-ba91-474e-a2de-ea5a2a328e71" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_FinancingReceivableRecordedInvestmentEqualToOrGreaterThanThirtyDaysPastDue_198a8ba9-f168-49b4-ba34-d693bb320371" xlink:href="fcf-20200331.xsd#fcf_FinancingReceivableRecordedInvestmentEqualToOrGreaterThanThirtyDaysPastDue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome_f4f8d61c-ba91-474e-a2de-ea5a2a328e71" xlink:to="loc_fcf_FinancingReceivableRecordedInvestmentEqualToOrGreaterThanThirtyDaysPastDue_198a8ba9-f168-49b4-ba34-d693bb320371" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentCurrent_c863f2e8-53b2-4656-ae5a-f8815a0530e2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestmentCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome_f4f8d61c-ba91-474e-a2de-ea5a2a328e71" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentCurrent_c863f2e8-53b2-4656-ae5a-f8815a0530e2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDue_5501994d-31fe-4478-81a8-855ad4788c25" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestmentPastDue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome_f4f8d61c-ba91-474e-a2de-ea5a2a328e71" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDue_5501994d-31fe-4478-81a8-855ad4788c25" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesRecordedInvestmentandUnpaidPrincipalBalanceforImpairedLoanswithAssociatedAllowanceDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#LoansandAllowanceforCreditLossesRecordedInvestmentandUnpaidPrincipalBalanceforImpairedLoanswithAssociatedAllowanceDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesRecordedInvestmentandUnpaidPrincipalBalanceforImpairedLoanswithAssociatedAllowanceDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTroubledDebtRestructuredLoansandCommitmentsDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#LoansandAllowanceforCreditLossesTroubledDebtRestructuredLoansandCommitmentsDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTroubledDebtRestructuredLoansandCommitmentsDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTroubledDebtRestructuringsIdentifiedDuringPeriodDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#LoansandAllowanceforCreditLossesTroubledDebtRestructuringsIdentifiedDuringPeriodDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTroubledDebtRestructuringsIdentifiedDuringPeriodDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTroubledDebtRestructuringis90DaysorMorePastDueDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#LoansandAllowanceforCreditLossesTroubledDebtRestructuringis90DaysorMorePastDueDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTroubledDebtRestructuringis90DaysorMorePastDueDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesAllowanceforCreditLossesDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#LoansandAllowanceforCreditLossesAllowanceforCreditLossesDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesAllowanceforCreditLossesDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_e31746c5-e8cc-4fa0-8d55-011e25fae750" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1_2c21e36f-b413-487e-9ebd-88d78a8bf85d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_e31746c5-e8cc-4fa0-8d55-011e25fae750" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1_2c21e36f-b413-487e-9ebd-88d78a8bf85d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment_a2f2e5b7-ee94-4760-a69f-9f6e3d28aa77" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_e31746c5-e8cc-4fa0-8d55-011e25fae750" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment_a2f2e5b7-ee94-4760-a69f-9f6e3d28aa77" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LeasesLeases" xlink:type="simple" xlink:href="fcf-20200331.xsd#LeasesLeases"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LeasesLeases" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LeasesLeaseLiabilityMaturityTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#LeasesLeaseLiabilityMaturityTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LeasesLeaseLiabilityMaturityTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LeasesLeaseAssetsandLiabilitiesTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#LeasesLeaseAssetsandLiabilitiesTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LeasesLeaseAssetsandLiabilitiesTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LeasesOperatingLeaseAssetsandLiabilitiesDetails" xlink:type="simple" xlink:href="fcf-20200331.xsd#LeasesOperatingLeaseAssetsandLiabilitiesDetails"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LeasesOperatingLeaseAssetsandLiabilitiesDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LeasesLeaseLiablityMaturityDetails" xlink:type="simple" xlink:href="fcf-20200331.xsd#LeasesLeaseLiablityMaturityDetails"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LeasesLeaseLiablityMaturityDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/LeasesTopic842AdditionalInformationDetailsDetails" xlink:type="simple" xlink:href="fcf-20200331.xsd#LeasesTopic842AdditionalInformationDetailsDetails"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/LeasesTopic842AdditionalInformationDetailsDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/IncomeTaxes" xlink:type="simple" xlink:href="fcf-20200331.xsd#IncomeTaxes"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/IncomeTaxes" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilities" xlink:type="simple" xlink:href="fcf-20200331.xsd#FairValuesofAssetsandLiabilities"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilities" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#FairValuesofAssetsandLiabilitiesTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesQuantitativeInputsandAssumptionsUsedinLevel3FairValueMeasurementsDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#FairValuesofAssetsandLiabilitiesQuantitativeInputsandAssumptionsUsedinLevel3FairValueMeasurementsDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesQuantitativeInputsandAssumptionsUsedinLevel3FairValueMeasurementsDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesScheduleofChangesinLevel3AssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#FairValuesofAssetsandLiabilitiesScheduleofChangesinLevel3AssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesScheduleofChangesinLevel3AssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesScheduleofAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#FairValuesofAssetsandLiabilitiesScheduleofAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesScheduleofAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_9f35d7f2-5b47-483a-8c30-a1b1c11705c1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecurities_d9592ac1-b04a-4119-a6e1-22c2b7c2bcde" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AvailableForSaleSecurities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_9f35d7f2-5b47-483a-8c30-a1b1c11705c1" xlink:to="loc_us-gaap_AvailableForSaleSecurities_d9592ac1-b04a-4119-a6e1-22c2b7c2bcde" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherInvestments_2444e92a-0355-476d-9a61-82ca4c333c8a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherInvestments"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_9f35d7f2-5b47-483a-8c30-a1b1c11705c1" xlink:to="loc_us-gaap_OtherInvestments_2444e92a-0355-476d-9a61-82ca4c333c8a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansHeldForSaleFairValueDisclosure_6c263732-31f3-4f31-aa1a-827492c4d731" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LoansHeldForSaleFairValueDisclosure"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_9f35d7f2-5b47-483a-8c30-a1b1c11705c1" xlink:to="loc_us-gaap_LoansHeldForSaleFairValueDisclosure_6c263732-31f3-4f31-aa1a-827492c4d731" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsFairValueDisclosure_23b63f1a-23d6-4d55-94c7-6792e75193cb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherAssetsFairValueDisclosure"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_9f35d7f2-5b47-483a-8c30-a1b1c11705c1" xlink:to="loc_us-gaap_OtherAssetsFairValueDisclosure_23b63f1a-23d6-4d55-94c7-6792e75193cb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_b52de320-e99e-4f11-b4e4-43c54e5a8a26" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesFairValueDisclosure_e1a06c22-75cd-47de-9bcf-bcef53cf179c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherLiabilitiesFairValueDisclosure"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosure_b52de320-e99e-4f11-b4e4-43c54e5a8a26" xlink:to="loc_us-gaap_OtherLiabilitiesFairValueDisclosure_e1a06c22-75cd-47de-9bcf-bcef53cf179c" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesAdditionalInformationDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#FairValuesofAssetsandLiabilitiesAdditionalInformationDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesAdditionalInformationDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesScheduleofAssetsMeasuredonNonRecurringBasisDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#FairValuesofAssetsandLiabilitiesScheduleofAssetsMeasuredonNonRecurringBasisDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesScheduleofAssetsMeasuredonNonRecurringBasisDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_95e84068-b089-4b4f-827e-357c55a8f411" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_ImpairedLoansFairValue_01b66b7e-d006-4d43-8d39-1d9c85ab1bb7" xlink:href="fcf-20200331.xsd#fcf_ImpairedLoansFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_95e84068-b089-4b4f-827e-357c55a8f411" xlink:to="loc_fcf_ImpairedLoansFairValue_01b66b7e-d006-4d43-8d39-1d9c85ab1bb7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_OtherRealEstateOwnedAssetsFairValue_a08dc8ed-ca3c-424e-aecb-392c79886581" xlink:href="fcf-20200331.xsd#fcf_OtherRealEstateOwnedAssetsFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_95e84068-b089-4b4f-827e-357c55a8f411" xlink:to="loc_fcf_OtherRealEstateOwnedAssetsFairValue_a08dc8ed-ca3c-424e-aecb-392c79886581" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesLossesRealizedonAssetsMeasuredonNonRecurringBasisDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#FairValuesofAssetsandLiabilitiesLossesRealizedonAssetsMeasuredonNonRecurringBasisDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesLossesRealizedonAssetsMeasuredonNonRecurringBasisDetail" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLoss_a8bfc09f-a159-4c5c-9bd1-df9e0f26980a" xlink:href="fcf-20200331.xsd#fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLossesOnImpairedLoans_1e2c1333-aba9-498b-a60b-1294fc42aa57" xlink:href="fcf-20200331.xsd#fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLossesOnImpairedLoans"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLoss_a8bfc09f-a159-4c5c-9bd1-df9e0f26980a" xlink:to="loc_fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLossesOnImpairedLoans_1e2c1333-aba9-498b-a60b-1294fc42aa57" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLossesOnOtherRealEstateOwned_9de1b84f-461f-4812-b732-0d4289e4fa4c" xlink:href="fcf-20200331.xsd#fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLossesOnOtherRealEstateOwned"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLoss_a8bfc09f-a159-4c5c-9bd1-df9e0f26980a" xlink:to="loc_fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLossesOnOtherRealEstateOwned_9de1b84f-461f-4812-b732-0d4289e4fa4c" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesCarryingAmountsandFairValuesofFinancialInstrumentsDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#FairValuesofAssetsandLiabilitiesCarryingAmountsandFairValuesofFinancialInstrumentsDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesCarryingAmountsandFairValuesofFinancialInstrumentsDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/Derivatives" xlink:type="simple" xlink:href="fcf-20200331.xsd#Derivatives"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/Derivatives" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/DerivativesTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#DerivativesTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/DerivativesTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/DerivativesAdditionalInformationDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#DerivativesAdditionalInformationDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/DerivativesAdditionalInformationDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/DerivativesCreditValueAdjustmentRecordedRelatedtoNotionalAmountofDerivativesOutstandingDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#DerivativesCreditValueAdjustmentRecordedRelatedtoNotionalAmountofDerivativesOutstandingDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/DerivativesCreditValueAdjustmentRecordedRelatedtoNotionalAmountofDerivativesOutstandingDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/DerivativesScheduleofChangesinFairValueofDerivativeAssetsandLiabilitiesDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#DerivativesScheduleofChangesinFairValueofDerivativeAssetsandLiabilitiesDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/DerivativesScheduleofChangesinFairValueofDerivativeAssetsandLiabilitiesDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/Goodwill" xlink:type="simple" xlink:href="fcf-20200331.xsd#Goodwill"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/Goodwill" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/GoodwillAdditionalInformationDetail" xlink:type="simple" xlink:href="fcf-20200331.xsd#GoodwillAdditionalInformationDetail"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/GoodwillAdditionalInformationDetail" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/SubordinatedDebenturesSubordinatedDebenturesOutstanding" xlink:type="simple" xlink:href="fcf-20200331.xsd#SubordinatedDebenturesSubordinatedDebenturesOutstanding"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/SubordinatedDebenturesSubordinatedDebenturesOutstanding" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/SubordinatedDebenturesSubordinatedDebenturesOutstandingTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#SubordinatedDebenturesSubordinatedDebenturesOutstandingTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/SubordinatedDebenturesSubordinatedDebenturesOutstandingTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/SubordinatedDebenturesScheduleofSubordinatedDebenturesOutstandingDetails" xlink:type="simple" xlink:href="fcf-20200331.xsd#SubordinatedDebenturesScheduleofSubordinatedDebenturesOutstandingDetails"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/SubordinatedDebenturesScheduleofSubordinatedDebenturesOutstandingDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/SubordinatedDebenturesSubordinatedDebenturesAdditionalInformationDetails" xlink:type="simple" xlink:href="fcf-20200331.xsd#SubordinatedDebenturesSubordinatedDebenturesAdditionalInformationDetails"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/SubordinatedDebenturesSubordinatedDebenturesAdditionalInformationDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/RevenueRecognitionRebenueRecognition" xlink:type="simple" xlink:href="fcf-20200331.xsd#RevenueRecognitionRebenueRecognition"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/RevenueRecognitionRebenueRecognition" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/RevenueRecognitionRevenueRecogntionTables" xlink:type="simple" xlink:href="fcf-20200331.xsd#RevenueRecognitionRevenueRecogntionTables"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/RevenueRecognitionRevenueRecogntionTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/RevenueRecognitionRevenueRecognitionDetails" xlink:type="simple" xlink:href="fcf-20200331.xsd#RevenueRecognitionRevenueRecognitionDetails"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/RevenueRecognitionRevenueRecognitionDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.fcbanking.com/role/RevenueRecognitionInScopeandOutofScopeRevenueStreams" xlink:type="simple" xlink:href="fcf-20200331.xsd#RevenueRecognitionInScopeandOutofScopeRevenueStreams"/>
  <link:calculationLink xlink:role="http://www.fcbanking.com/role/RevenueRecognitionInScopeandOutofScopeRevenueStreams" xlink:type="extended"/>
</link:linkbase>
