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

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2021 Workiva-->
<!--r:56c3ef6e-f7b5-4044-a98e-7c50e63d966c,g:d2964efa-be58-49b8-b0ca-59e2f6bf2520-->
<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.intlfcstone.com/role/Cover" xlink:type="simple" xlink:href="intl-20201231.xsd#Cover"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/Cover" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CondensedConsolidatedBalanceSheets" xlink:type="simple" xlink:href="intl-20201231.xsd#CondensedConsolidatedBalanceSheets"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CondensedConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_3e656709-ab33-4881-a80d-10bc5e3bdb0a" 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_72f9f087-74de-462e-8d9a-df7265571c27" 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_3e656709-ab33-4881-a80d-10bc5e3bdb0a" xlink:to="loc_us-gaap_Liabilities_72f9f087-74de-462e-8d9a-df7265571c27" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_5c6bac3f-7171-4fd9-abea-d22c1fd381c2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_3e656709-ab33-4881-a80d-10bc5e3bdb0a" xlink:to="loc_us-gaap_CommitmentsAndContingencies_5c6bac3f-7171-4fd9-abea-d22c1fd381c2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_ee8de92d-0cca-4178-9c3c-35e1d3dbf4b5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_3e656709-ab33-4881-a80d-10bc5e3bdb0a" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_ee8de92d-0cca-4178-9c3c-35e1d3dbf4b5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" 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_Cash_7e745d75-b5c5-48b5-bcdd-1c844f843c09" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Cash"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_Cash_7e745d75-b5c5-48b5-bcdd-1c844f843c09" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndSecuritiesSegregatedUnderFederalAndOtherRegulations_d397102d-f932-4bcb-bfb2-faa07ae1a009" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndSecuritiesSegregatedUnderFederalAndOtherRegulations"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_CashAndSecuritiesSegregatedUnderFederalAndOtherRegulations_d397102d-f932-4bcb-bfb2-faa07ae1a009" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesPurchasedUnderAgreementsToResell_cb39eec4-458d-4161-a727-acf6c9c850ca" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesPurchasedUnderAgreementsToResell"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_SecuritiesPurchasedUnderAgreementsToResell_cb39eec4-458d-4161-a727-acf6c9c850ca" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesBorrowed_3f0fc3f8-b6b9-472e-a1c3-a87b6eb442fc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesBorrowed"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_SecuritiesBorrowed_3f0fc3f8-b6b9-472e-a1c3-a87b6eb442fc" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations_d66845a3-089a-4ca4-82f0-6e879a9ce680" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations_d66845a3-089a-4ca4-82f0-6e879a9ce680" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesFromCustomers_143c6d21-3b80-46bf-814d-0f790702c560" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReceivablesFromCustomers"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_ReceivablesFromCustomers_143c6d21-3b80-46bf-814d-0f790702c560" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_Notesreceivable_17a44461-dfb2-43ac-9664-561fcce20e93" xlink:href="intl-20201231.xsd#intl_Notesreceivable"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_intl_Notesreceivable_17a44461-dfb2-43ac-9664-561fcce20e93" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReceivable_65b253fb-608f-4625-8b15-de486a4a233e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxReceivable"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_IncomeTaxReceivable_65b253fb-608f-4625-8b15-de486a4a233e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentsOwnedAtFairValue_954ebc2b-dabb-40ee-9275-59048909104f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancialInstrumentsOwnedAtFairValue"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_FinancialInstrumentsOwnedAtFairValue_954ebc2b-dabb-40ee-9275-59048909104f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryGross_3a347335-a919-4c91-af60-1ee4a11c5764" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryGross"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_InventoryGross_3a347335-a919-4c91-af60-1ee4a11c5764" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_c4a67266-a363-4995-87fa-c20527431765" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredIncomeTaxAssetsNet"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_c4a67266-a363-4995-87fa-c20527431765" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_23354380-4b5c-4e08-9421-93f46a818ae6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="12" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_23354380-4b5c-4e08-9421-93f46a818ae6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_552fa93d-9955-490c-a217-553c2f828ae7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:calculationArc order="13" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_552fa93d-9955-490c-a217-553c2f828ae7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_GoodwillAndIntangibleAssetsNet_3a2ed569-7797-41ad-983a-57a9cfa83845" xlink:href="intl-20201231.xsd#intl_GoodwillAndIntangibleAssetsNet"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_intl_GoodwillAndIntangibleAssetsNet_3a2ed569-7797-41ad-983a-57a9cfa83845" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssets_8d9c3b42-c19a-476e-aa6f-df58ef3976ca" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssets"/>
    <link:calculationArc order="15" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_9e5bfc7b-0fa7-410c-88ab-e78cdb36d095" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssets_8d9c3b42-c19a-476e-aa6f-df58ef3976ca" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_61a38acf-07db-444f-82bc-a82150843519" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValueOutstanding_43cc00b9-45f0-4e66-9ae2-6e798bd3d338" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockValueOutstanding"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_61a38acf-07db-444f-82bc-a82150843519" xlink:to="loc_us-gaap_PreferredStockValueOutstanding_43cc00b9-45f0-4e66-9ae2-6e798bd3d338" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValueOutstanding_584722d5-2d1b-4e5c-b6b0-9b17654f140e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockValueOutstanding"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_61a38acf-07db-444f-82bc-a82150843519" xlink:to="loc_us-gaap_CommonStockValueOutstanding_584722d5-2d1b-4e5c-b6b0-9b17654f140e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValue_95a406e9-363e-4f4b-af62-9a722ceea398" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockValue"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_61a38acf-07db-444f-82bc-a82150843519" xlink:to="loc_us-gaap_TreasuryStockValue_95a406e9-363e-4f4b-af62-9a722ceea398" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_e55fea99-9645-4de4-bbf5-8e98185b4df0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_61a38acf-07db-444f-82bc-a82150843519" xlink:to="loc_us-gaap_AdditionalPaidInCapital_e55fea99-9645-4de4-bbf5-8e98185b4df0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_61b10b8e-0b23-47d1-9442-d3f432185c49" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_61a38acf-07db-444f-82bc-a82150843519" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_61b10b8e-0b23-47d1-9442-d3f432185c49" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_8617f63e-555c-4dd4-b167-9d72592b3777" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_61a38acf-07db-444f-82bc-a82150843519" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_8617f63e-555c-4dd4-b167-9d72592b3777" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_35d63cd9-66d3-46cc-9a57-3f61516bc65c" 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_AccountsPayableAndOtherAccruedLiabilities_a7fd4802-8bd3-4a55-b270-9b8cf17fe90f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsPayableAndOtherAccruedLiabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_35d63cd9-66d3-46cc-9a57-3f61516bc65c" xlink:to="loc_us-gaap_AccountsPayableAndOtherAccruedLiabilities_a7fd4802-8bd3-4a55-b270-9b8cf17fe90f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_ec850134-2baa-419f-9639-9bb1485f03fa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_35d63cd9-66d3-46cc-9a57-3f61516bc65c" xlink:to="loc_us-gaap_OperatingLeaseLiability_ec850134-2baa-419f-9639-9bb1485f03fa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_PayablesToCustomers_2fc90b61-679a-4af8-a43b-7f6f2543c9ae" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_PayablesToCustomers"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_35d63cd9-66d3-46cc-9a57-3f61516bc65c" xlink:to="loc_srt_PayablesToCustomers_2fc90b61-679a-4af8-a43b-7f6f2543c9ae" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_PayablesToBrokerDealersAndClearingOrganizations_b0290591-333d-4b39-aee8-7180423a5459" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_PayablesToBrokerDealersAndClearingOrganizations"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_35d63cd9-66d3-46cc-9a57-3f61516bc65c" xlink:to="loc_srt_PayablesToBrokerDealersAndClearingOrganizations_b0290591-333d-4b39-aee8-7180423a5459" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_b1a81d90-44f0-4a5e-8ca2-00b868eeebd2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCredit"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_35d63cd9-66d3-46cc-9a57-3f61516bc65c" xlink:to="loc_us-gaap_LineOfCredit_b1a81d90-44f0-4a5e-8ca2-00b868eeebd2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansPayable_da87e417-8691-4757-8ae2-c609b01ce946" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LoansPayable"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_35d63cd9-66d3-46cc-9a57-3f61516bc65c" xlink:to="loc_us-gaap_LoansPayable_da87e417-8691-4757-8ae2-c609b01ce946" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedIncomeTaxes_8a599f6c-f995-41e8-954d-7d194d85a5b5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccruedIncomeTaxes"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_35d63cd9-66d3-46cc-9a57-3f61516bc65c" xlink:to="loc_us-gaap_AccruedIncomeTaxes_8a599f6c-f995-41e8-954d-7d194d85a5b5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_eb5f7a8f-ed2f-41eb-b769-2419862565ef" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchase"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_35d63cd9-66d3-46cc-9a57-3f61516bc65c" xlink:to="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_eb5f7a8f-ed2f-41eb-b769-2419862565ef" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesLoaned_91580fd1-3b23-41e0-828d-d95223688611" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesLoaned"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_35d63cd9-66d3-46cc-9a57-3f61516bc65c" xlink:to="loc_us-gaap_SecuritiesLoaned_91580fd1-3b23-41e0-828d-d95223688611" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue_ede604be-31e8-413a-b306-5643d1dd39f0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_35d63cd9-66d3-46cc-9a57-3f61516bc65c" xlink:to="loc_us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue_ede604be-31e8-413a-b306-5643d1dd39f0" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CondensedConsolidatedBalanceSheetsParentheticals" xlink:type="simple" xlink:href="intl-20201231.xsd#CondensedConsolidatedBalanceSheetsParentheticals"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CondensedConsolidatedBalanceSheetsParentheticals" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CondensedConsolidatedIncomeStatements" xlink:type="simple" xlink:href="intl-20201231.xsd#CondensedConsolidatedIncomeStatements"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CondensedConsolidatedIncomeStatements" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesNetOfInterestExpense_f088038e-27c5-4571-bea1-111333a22aea" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesNetOfInterestExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_ebafa61d-0be3-400b-9911-eaea3facfb55" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GrossProfit"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_RevenuesNetOfInterestExpense_f088038e-27c5-4571-bea1-111333a22aea" xlink:to="loc_us-gaap_GrossProfit_ebafa61d-0be3-400b-9911-eaea3facfb55" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FloorBrokerageExchangeAndClearanceFees_e456a751-39d8-4cf7-ad77-0c1f54dec23c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FloorBrokerageExchangeAndClearanceFees"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_RevenuesNetOfInterestExpense_f088038e-27c5-4571-bea1-111333a22aea" xlink:to="loc_us-gaap_FloorBrokerageExchangeAndClearanceFees_e456a751-39d8-4cf7-ad77-0c1f54dec23c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpenseCommissionExpense_55ba9373-0618-4639-a48d-8d964a67a21e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoninterestExpenseCommissionExpense"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_RevenuesNetOfInterestExpense_f088038e-27c5-4571-bea1-111333a22aea" xlink:to="loc_us-gaap_NoninterestExpenseCommissionExpense_55ba9373-0618-4639-a48d-8d964a67a21e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_413e88d2-dd66-4987-b23d-2a185b51e50b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestExpense"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_RevenuesNetOfInterestExpense_f088038e-27c5-4571-bea1-111333a22aea" xlink:to="loc_us-gaap_InterestExpense_413e88d2-dd66-4987-b23d-2a185b51e50b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_InterestExpenseOnCorporateFunding_57631e5d-ee94-41ac-88f1-3525495f4269" xlink:href="intl-20201231.xsd#intl_InterestExpenseOnCorporateFunding"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_RevenuesNetOfInterestExpense_f088038e-27c5-4571-bea1-111333a22aea" xlink:to="loc_intl_InterestExpenseOnCorporateFunding_57631e5d-ee94-41ac-88f1-3525495f4269" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_3a62a89c-ffdb-48c1-a6f1-6e6f48f2d761" 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_RevenuesNetOfInterestExpense_7b1b3501-3099-4535-a5b8-5b4fc0a034af" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesNetOfInterestExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_3a62a89c-ffdb-48c1-a6f1-6e6f48f2d761" xlink:to="loc_us-gaap_RevenuesNetOfInterestExpense_7b1b3501-3099-4535-a5b8-5b4fc0a034af" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_4f88380d-6fba-4205-8e15-c440ac4cca22" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoninterestExpense"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_3a62a89c-ffdb-48c1-a6f1-6e6f48f2d761" xlink:to="loc_us-gaap_NoninterestExpense_4f88380d-6fba-4205-8e15-c440ac4cca22" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingGainsLosses_dd3e636e-c9c8-4d25-8480-ef0c8336c5af" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNonoperatingGainsLosses"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_3a62a89c-ffdb-48c1-a6f1-6e6f48f2d761" xlink:to="loc_us-gaap_OtherNonoperatingGainsLosses_dd3e636e-c9c8-4d25-8480-ef0c8336c5af" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_157af47a-0806-4e45-ad84-77f7473ef009" 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_8887fc4b-f7d1-4853-950c-49ca6bb0434b" 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_157af47a-0806-4e45-ad84-77f7473ef009" xlink:to="loc_us-gaap_LaborAndRelatedExpense_8887fc4b-f7d1-4853-950c-49ca6bb0434b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_Tradingsystemsandmarketinformation_15a31aa4-8dcc-433d-a5e9-cbfa6519fa08" xlink:href="intl-20201231.xsd#intl_Tradingsystemsandmarketinformation"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_157af47a-0806-4e45-ad84-77f7473ef009" xlink:to="loc_intl_Tradingsystemsandmarketinformation_15a31aa4-8dcc-433d-a5e9-cbfa6519fa08" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_23b4fc81-ce6f-4ca3-b7f8-a543caf5db4d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProfessionalFees"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_157af47a-0806-4e45-ad84-77f7473ef009" xlink:to="loc_us-gaap_ProfessionalFees_23b4fc81-ce6f-4ca3-b7f8-a543caf5db4d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InformationTechnologyAndDataProcessing_e38a6c4b-9634-4170-872d-ada282e09168" 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_157af47a-0806-4e45-ad84-77f7473ef009" xlink:to="loc_us-gaap_InformationTechnologyAndDataProcessing_e38a6c4b-9634-4170-872d-ada282e09168" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OccupancyNet_7bc263cd-2719-41ed-9197-1252921502a6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OccupancyNet"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_157af47a-0806-4e45-ad84-77f7473ef009" xlink:to="loc_us-gaap_OccupancyNet_7bc263cd-2719-41ed-9197-1252921502a6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_98aea74e-7e00-482e-8c04-dbc2afea8fa1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SellingAndMarketingExpense"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_157af47a-0806-4e45-ad84-77f7473ef009" xlink:to="loc_us-gaap_SellingAndMarketingExpense_98aea74e-7e00-482e-8c04-dbc2afea8fa1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TravelAndEntertainmentExpense_5e69d56a-1ea1-4a5b-ad0a-ec348bcb1a39" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TravelAndEntertainmentExpense"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_157af47a-0806-4e45-ad84-77f7473ef009" xlink:to="loc_us-gaap_TravelAndEntertainmentExpense_5e69d56a-1ea1-4a5b-ad0a-ec348bcb1a39" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Communication_6d87f607-da01-4062-9b4b-8305a1870dff" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Communication"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_157af47a-0806-4e45-ad84-77f7473ef009" xlink:to="loc_us-gaap_Communication_6d87f607-da01-4062-9b4b-8305a1870dff" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_f24466b1-2556-46ff-a561-4ee3b3c661c9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_157af47a-0806-4e45-ad84-77f7473ef009" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_f24466b1-2556-46ff-a561-4ee3b3c661c9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_93f4eadb-b016-4fb9-9cae-5170578891f0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_157af47a-0806-4e45-ad84-77f7473ef009" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_93f4eadb-b016-4fb9-9cae-5170578891f0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoninterestExpense_a367bae7-f587-44f3-958c-c2e061b885da" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNoninterestExpense"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoninterestExpense_157af47a-0806-4e45-ad84-77f7473ef009" xlink:to="loc_us-gaap_OtherNoninterestExpense_a367bae7-f587-44f3-958c-c2e061b885da" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_771178e3-d69c-4030-8bb0-15d3410e7c75" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Revenues"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_Salesofphysicalcommodities_f773d59c-5562-4eed-8c42-9f339d0a3f02" xlink:href="intl-20201231.xsd#intl_Salesofphysicalcommodities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Revenues_771178e3-d69c-4030-8bb0-15d3410e7c75" xlink:to="loc_intl_Salesofphysicalcommodities_f773d59c-5562-4eed-8c42-9f339d0a3f02" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrincipalTransactionsRevenue_9949a9d1-faa9-4335-9b2d-d0645a95449c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PrincipalTransactionsRevenue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Revenues_771178e3-d69c-4030-8bb0-15d3410e7c75" xlink:to="loc_us-gaap_PrincipalTransactionsRevenue_9949a9d1-faa9-4335-9b2d-d0645a95449c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BrokerageCommissionsRevenue_6de825a2-e616-4c3a-9faa-6cad04935361" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BrokerageCommissionsRevenue"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Revenues_771178e3-d69c-4030-8bb0-15d3410e7c75" xlink:to="loc_us-gaap_BrokerageCommissionsRevenue_6de825a2-e616-4c3a-9faa-6cad04935361" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_Consultingmanagementandaccountfees_1e00ec4b-63c0-4237-aa80-9431824d2a51" xlink:href="intl-20201231.xsd#intl_Consultingmanagementandaccountfees"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Revenues_771178e3-d69c-4030-8bb0-15d3410e7c75" xlink:to="loc_intl_Consultingmanagementandaccountfees_1e00ec4b-63c0-4237-aa80-9431824d2a51" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOperating_453af20d-afbd-4168-bed8-dbc9f0ef6bd5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestIncomeOperating"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Revenues_771178e3-d69c-4030-8bb0-15d3410e7c75" xlink:to="loc_us-gaap_InterestIncomeOperating_453af20d-afbd-4168-bed8-dbc9f0ef6bd5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_f03b0c91-db21-4e5e-90e5-4a93dba67b54" 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_7281a691-eac0-4200-95bb-e468083b4d23" 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_f03b0c91-db21-4e5e-90e5-4a93dba67b54" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_7281a691-eac0-4200-95bb-e468083b4d23" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_4d1658f2-96bf-4de7-9974-0bfe19c3acef" 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_f03b0c91-db21-4e5e-90e5-4a93dba67b54" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_4d1658f2-96bf-4de7-9974-0bfe19c3acef" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_797cd1c3-31af-4c32-8390-ff7c8a7fc393" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GrossProfit"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_f99c18cf-7953-446e-a5c1-4081c4d8eafe" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Revenues"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_797cd1c3-31af-4c32-8390-ff7c8a7fc393" xlink:to="loc_us-gaap_Revenues_f99c18cf-7953-446e-a5c1-4081c4d8eafe" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization_5aec9463-3334-4707-97d7-dbbd9eca44b1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_797cd1c3-31af-4c32-8390-ff7c8a7fc393" xlink:to="loc_us-gaap_CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization_5aec9463-3334-4707-97d7-dbbd9eca44b1" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CondensedConsolidatedStatementsofComprehensiveIncome" xlink:type="simple" xlink:href="intl-20201231.xsd#CondensedConsolidatedStatementsofComprehensiveIncome"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CondensedConsolidatedStatementsofComprehensiveIncome" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_e3d72c50-6f04-4faa-8c43-780bc054d6d2" 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_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_859d9940-d1b7-4e1a-82cc-3b4f38173e08" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_e3d72c50-6f04-4faa-8c43-780bc054d6d2" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_859d9940-d1b7-4e1a-82cc-3b4f38173e08" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_fcfc261c-b7c7-4ceb-a662-15db8599e67e" 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_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_69149667-d120-4227-a875-351e154b2345" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_fcfc261c-b7c7-4ceb-a662-15db8599e67e" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_69149667-d120-4227-a875-351e154b2345" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_82772e7c-df9e-464f-bf17-3f865d8816a5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_fcfc261c-b7c7-4ceb-a662-15db8599e67e" xlink:to="loc_us-gaap_NetIncomeLoss_82772e7c-df9e-464f-bf17-3f865d8816a5" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CondensedConsolidatedCashFlows" xlink:type="simple" xlink:href="intl-20201231.xsd#CondensedConsolidatedCashFlows"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CondensedConsolidatedCashFlows" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" 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_ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess_017a1158-126c-4686-bb30-796fb0b71a9e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" xlink:to="loc_us-gaap_ProceedsFromRepaymentsOfShortTermDebtMaturingInThreeMonthsOrLess_017a1158-126c-4686-bb30-796fb0b71a9e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths_aebabf22-a068-4949-985b-da9a37043f6a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" xlink:to="loc_us-gaap_ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths_aebabf22-a068-4949-985b-da9a37043f6a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths_1d21e760-968d-462a-8ced-57b2e85fa825" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" xlink:to="loc_us-gaap_RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths_1d21e760-968d-462a-8ced-57b2e85fa825" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_72a9e465-9be1-4c48-972f-039c5c338044" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_72a9e465-9be1-4c48-972f-039c5c338044" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfSecuredDebt_adc0f45a-258a-4724-9516-640a867cb2b5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RepaymentsOfSecuredDebt"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" xlink:to="loc_us-gaap_RepaymentsOfSecuredDebt_adc0f45a-258a-4724-9516-640a867cb2b5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfNotesPayable_7e42d008-957d-45cd-b1ac-df251ed9a055" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RepaymentsOfNotesPayable"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" xlink:to="loc_us-gaap_RepaymentsOfNotesPayable_7e42d008-957d-45cd-b1ac-df251ed9a055" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_833dcaf2-b472-422a-a92f-08aa55c2c671" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_833dcaf2-b472-422a-a92f-08aa55c2c671" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_7b9caaed-a53f-4a86-991e-fd63a3e489de" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_7b9caaed-a53f-4a86-991e-fd63a3e489de" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_30984653-5e75-4c81-aa8d-056bfede1c06" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_30984653-5e75-4c81-aa8d-056bfede1c06" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_fb1f69ef-d532-4a04-8423-b29d092eebf8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_fb1f69ef-d532-4a04-8423-b29d092eebf8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromNotesPayable_5042caf3-baea-4da1-ad46-38440fd3e25b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProceedsFromNotesPayable"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_f8cb43a0-461e-48e4-9939-bc090997eb84" xlink:to="loc_us-gaap_ProceedsFromNotesPayable_5042caf3-baea-4da1-ad46-38440fd3e25b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_408d8063-a557-4cb5-bce6-ae1e2bb9f102" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Cash_5363cc12-fb44-49be-98d5-de1feeff55b9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Cash"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_408d8063-a557-4cb5-bce6-ae1e2bb9f102" xlink:to="loc_us-gaap_Cash_5363cc12-fb44-49be-98d5-de1feeff55b9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_DepositsWithAndReceivablesFromClearingOrganizationsSegregatedUnderCommodityExchangeActRegulation_38684e4c-8612-4e4c-b775-a8e71465f31d" xlink:href="intl-20201231.xsd#intl_DepositsWithAndReceivablesFromClearingOrganizationsSegregatedUnderCommodityExchangeActRegulation"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_408d8063-a557-4cb5-bce6-ae1e2bb9f102" xlink:to="loc_intl_DepositsWithAndReceivablesFromClearingOrganizationsSegregatedUnderCommodityExchangeActRegulation_38684e4c-8612-4e4c-b775-a8e71465f31d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashSegregatedUnderCommodityExchangeActRegulation_dc3b77f1-8829-4e6d-9af9-b56a7b74d7f5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashSegregatedUnderCommodityExchangeActRegulation"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_408d8063-a557-4cb5-bce6-ae1e2bb9f102" xlink:to="loc_us-gaap_CashSegregatedUnderCommodityExchangeActRegulation_dc3b77f1-8829-4e6d-9af9-b56a7b74d7f5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesSegregatedUnderOtherRegulations_660d9c0c-159f-4212-a3c0-0864649c1864" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesSegregatedUnderOtherRegulations"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_408d8063-a557-4cb5-bce6-ae1e2bb9f102" xlink:to="loc_us-gaap_SecuritiesSegregatedUnderOtherRegulations_660d9c0c-159f-4212-a3c0-0864649c1864" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_SecuritiesAndOtherAssetsSegregatedFairValue_b57c7677-d33b-4e09-b35b-b0671be71651" xlink:href="intl-20201231.xsd#intl_SecuritiesAndOtherAssetsSegregatedFairValue"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_408d8063-a557-4cb5-bce6-ae1e2bb9f102" xlink:to="loc_intl_SecuritiesAndOtherAssetsSegregatedFairValue_b57c7677-d33b-4e09-b35b-b0671be71651" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_caf79d09-1d73-4148-9025-f9f8c2c37b49" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_6b03bcb0-60fe-4738-bd0c-5e42289790d2" 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_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_caf79d09-1d73-4148-9025-f9f8c2c37b49" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_6b03bcb0-60fe-4738-bd0c-5e42289790d2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_5637cd9b-490c-4904-90e8-fc656eaf0d87" 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_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_caf79d09-1d73-4148-9025-f9f8c2c37b49" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_5637cd9b-490c-4904-90e8-fc656eaf0d87" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_6fba7e72-5526-490f-b31d-ceb88245939b" 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_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_caf79d09-1d73-4148-9025-f9f8c2c37b49" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_6fba7e72-5526-490f-b31d-ceb88245939b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_a96fbcbb-514b-4d6a-941d-c6bad8dc3169" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_caf79d09-1d73-4148-9025-f9f8c2c37b49" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_a96fbcbb-514b-4d6a-941d-c6bad8dc3169" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_7080afa8-d0ee-4a41-80ff-1e2f151eb048" 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_PaymentsToAcquireBusinessesNetOfCashAcquired_a4693294-14ef-4f64-baba-af3ca5d3a98d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_7080afa8-d0ee-4a41-80ff-1e2f151eb048" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_a4693294-14ef-4f64-baba-af3ca5d3a98d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_6e44a5fa-9999-4acf-896a-b11f21647f8e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_7080afa8-d0ee-4a41-80ff-1e2f151eb048" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_6e44a5fa-9999-4acf-896a-b11f21647f8e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" 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_3fc810ac-0485-4584-838a-e93e19cd8776" 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_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_NetIncomeLoss_3fc810ac-0485-4584-838a-e93e19cd8776" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_ff0bc600-ecb7-4ec2-a73c-225ab4554be6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_DepreciationAndAmortization_ff0bc600-ecb7-4ec2-a73c-225ab4554be6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_46e4bd46-575d-4aab-9d59-1648b9fe9509" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_46e4bd46-575d-4aab-9d59-1648b9fe9509" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_485d73ce-6534-4db7-bfa2-99c2dc268e09" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_485d73ce-6534-4db7-bfa2-99c2dc268e09" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_64b5da1d-9157-48a5-b78c-b33c9d466453" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_64b5da1d-9157-48a5-b78c-b33c9d466453" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_be833a36-1bff-42e9-bcbc-1ca29c138ac8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_ShareBasedCompensation_be833a36-1bff-42e9-bcbc-1ca29c138ac8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInRestrictedCashAndInvestmentsForOperatingActivities_534fdfce-9c56-4b7e-ae2a-54e879b2ed4d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInRestrictedCashAndInvestmentsForOperatingActivities"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInRestrictedCashAndInvestmentsForOperatingActivities_534fdfce-9c56-4b7e-ae2a-54e879b2ed4d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInReceivablesUnderRepurchaseAgreements_b63ab339-83dc-4007-bad5-839a8821ab52" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInReceivablesUnderRepurchaseAgreements"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInReceivablesUnderRepurchaseAgreements_b63ab339-83dc-4007-bad5-839a8821ab52" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInSecuritiesBorrowed_a58f7620-576b-44b6-a246-d52c714b50c7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInSecuritiesBorrowed"/>
    <link:calculationArc order="9" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInSecuritiesBorrowed_a58f7620-576b-44b6-a246-d52c714b50c7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_IncreaseDecreaseInDepositsWithAndReceivablesFromBrokerDealersClearingOrganizationsAndCounterparties_0551186a-3cf9-40de-a796-97921a61a73f" xlink:href="intl-20201231.xsd#intl_IncreaseDecreaseInDepositsWithAndReceivablesFromBrokerDealersClearingOrganizationsAndCounterparties"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_intl_IncreaseDecreaseInDepositsWithAndReceivablesFromBrokerDealersClearingOrganizationsAndCounterparties_0551186a-3cf9-40de-a796-97921a61a73f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_0ebc455c-7e14-4b0c-a007-4d1e48989f75" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:calculationArc order="11" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_0ebc455c-7e14-4b0c-a007-4d1e48989f75" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInNotesReceivables_5ff7fe35-8198-4644-8c6e-832bb4bd0a6b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInNotesReceivables"/>
    <link:calculationArc order="12" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInNotesReceivables_5ff7fe35-8198-4644-8c6e-832bb4bd0a6b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInIncomeTaxesReceivable_d2ad3849-7fe0-4159-924d-c5786fad787b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInIncomeTaxesReceivable"/>
    <link:calculationArc order="13" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInIncomeTaxesReceivable_d2ad3849-7fe0-4159-924d-c5786fad787b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities_1e84354c-8bc0-4655-9870-8ce7c52f2da6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities"/>
    <link:calculationArc order="14" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInFinancialInstrumentsUsedInOperatingActivities_1e84354c-8bc0-4655-9870-8ce7c52f2da6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_38499df4-88e6-426e-97a3-06b50b16f661" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInInventories"/>
    <link:calculationArc order="15" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_38499df4-88e6-426e-97a3-06b50b16f661" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_3eb5e119-60ea-4dcc-a429-13e403c20c11" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:calculationArc order="16" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_3eb5e119-60ea-4dcc-a429-13e403c20c11" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_2ddb25f0-99cf-4d5e-a61c-f2f83da1c84c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities"/>
    <link:calculationArc order="17" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_2ddb25f0-99cf-4d5e-a61c-f2f83da1c84c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_IncreaseDecreaseInOperatingLeaseLiabilities_a6048ed0-e138-4d6b-ac1b-182803a45681" xlink:href="intl-20201231.xsd#intl_IncreaseDecreaseInOperatingLeaseLiabilities"/>
    <link:calculationArc order="18" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_intl_IncreaseDecreaseInOperatingLeaseLiabilities_a6048ed0-e138-4d6b-ac1b-182803a45681" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPayablesToCustomers_7d825c98-21cf-4fe3-94fa-5922b4a47957" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInPayablesToCustomers"/>
    <link:calculationArc order="19" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInPayablesToCustomers_7d825c98-21cf-4fe3-94fa-5922b4a47957" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPayablesToBrokerDealers_c369194f-c225-4451-8cda-7e075388655a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInPayablesToBrokerDealers"/>
    <link:calculationArc order="20" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInPayablesToBrokerDealers_c369194f-c225-4451-8cda-7e075388655a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_62eb0630-f6fc-488b-bf0c-ad670a282a07" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable"/>
    <link:calculationArc order="21" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_62eb0630-f6fc-488b-bf0c-ad670a282a07" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPayablesUnderRepurchaseAgreements_e4b4970b-eb2f-4cf6-99a0-ca39713d64c9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInPayablesUnderRepurchaseAgreements"/>
    <link:calculationArc order="22" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInPayablesUnderRepurchaseAgreements_e4b4970b-eb2f-4cf6-99a0-ca39713d64c9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInSecuritiesLoanedTransactions_d18d8ed3-c02e-40a1-a771-20b992ad0b03" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInSecuritiesLoanedTransactions"/>
    <link:calculationArc order="23" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInSecuritiesLoanedTransactions_d18d8ed3-c02e-40a1-a771-20b992ad0b03" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInFinancialInstrumentsSoldNotYetPurchased_41242c3f-3df3-4a05-8bd4-1acafef11f4a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInFinancialInstrumentsSoldNotYetPurchased"/>
    <link:calculationArc order="24" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_IncreaseDecreaseInFinancialInstrumentsSoldNotYetPurchased_41242c3f-3df3-4a05-8bd4-1acafef11f4a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_a57137b0-03db-4301-a322-de8d296416fe" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense"/>
    <link:calculationArc order="25" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_fd0ffdb8-6d80-4823-91bd-dca78a7fd56c" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAssetAmortizationExpense_a57137b0-03db-4301-a322-de8d296416fe" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashOrPartNoncashAcquisitionNetNonmonetaryAssetsAcquiredLiabilitiesAssumed1_dcada14d-b2b1-4c0f-a9dd-a8967c3eaccf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncashOrPartNoncashAcquisitionNetNonmonetaryAssetsAcquiredLiabilitiesAssumed1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashOrPartNoncashAcquisitionValueOfLiabilitiesAssumed1_67cc4f29-cd7d-4c91-81a6-56a4e7b16285" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncashOrPartNoncashAcquisitionValueOfLiabilitiesAssumed1"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoncashOrPartNoncashAcquisitionNetNonmonetaryAssetsAcquiredLiabilitiesAssumed1_dcada14d-b2b1-4c0f-a9dd-a8967c3eaccf" xlink:to="loc_us-gaap_NoncashOrPartNoncashAcquisitionValueOfLiabilitiesAssumed1_67cc4f29-cd7d-4c91-81a6-56a4e7b16285" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashOrPartNoncashAcquisitionValueOfAssetsAcquired1_3329e9e0-b233-42f7-ae88-84eed15970a7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncashOrPartNoncashAcquisitionValueOfAssetsAcquired1"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NoncashOrPartNoncashAcquisitionNetNonmonetaryAssetsAcquiredLiabilitiesAssumed1_dcada14d-b2b1-4c0f-a9dd-a8967c3eaccf" xlink:to="loc_us-gaap_NoncashOrPartNoncashAcquisitionValueOfAssetsAcquired1_3329e9e0-b233-42f7-ae88-84eed15970a7" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CondensedConsolidatedStatementofStockholdersEquity" xlink:type="simple" xlink:href="intl-20201231.xsd#CondensedConsolidatedStatementofStockholdersEquity"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CondensedConsolidatedStatementofStockholdersEquity" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/BasisofPresentationandConsolidationandAccountingStandardsAdopted" xlink:type="simple" xlink:href="intl-20201231.xsd#BasisofPresentationandConsolidationandAccountingStandardsAdopted"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/BasisofPresentationandConsolidationandAccountingStandardsAdopted" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/BasisofPresentationandConsolidationandAccountingStandardsAdoptedPolicies" xlink:type="simple" xlink:href="intl-20201231.xsd#BasisofPresentationandConsolidationandAccountingStandardsAdoptedPolicies"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/BasisofPresentationandConsolidationandAccountingStandardsAdoptedPolicies" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/BasisofPresentationandConsolidationandAccountingStandardsAdoptedDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#BasisofPresentationandConsolidationandAccountingStandardsAdoptedDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/BasisofPresentationandConsolidationandAccountingStandardsAdoptedDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/EarningsperShare" xlink:type="simple" xlink:href="intl-20201231.xsd#EarningsperShare"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/EarningsperShare" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/EarningsperShareTables" xlink:type="simple" xlink:href="intl-20201231.xsd#EarningsperShareTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/EarningsperShareTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/EarningsperShareEPSReconciliationDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#EarningsperShareEPSReconciliationDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/EarningsperShareEPSReconciliationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_intl_Incomefromcontinuingoperationsallocatedtocommonshareholders_e02aa48e-2375-4593-9a43-49c11795931f" xlink:href="intl-20201231.xsd#intl_Incomefromcontinuingoperationsallocatedtocommonshareholders"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_UndistributedEarningsAllocatedtoParticipatingSecuritiesContinuingOperations_d6a8c0ca-d60e-472b-8cff-6bdf3790028f" xlink:href="intl-20201231.xsd#intl_UndistributedEarningsAllocatedtoParticipatingSecuritiesContinuingOperations"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_intl_Incomefromcontinuingoperationsallocatedtocommonshareholders_e02aa48e-2375-4593-9a43-49c11795931f" xlink:to="loc_intl_UndistributedEarningsAllocatedtoParticipatingSecuritiesContinuingOperations_d6a8c0ca-d60e-472b-8cff-6bdf3790028f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperations_8dae4a57-6228-4764-9e29-a1d448794b1d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperations"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_intl_Incomefromcontinuingoperationsallocatedtocommonshareholders_e02aa48e-2375-4593-9a43-49c11795931f" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperations_8dae4a57-6228-4764-9e29-a1d448794b1d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/EarningsperShareNarrativeDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#EarningsperShareNarrativeDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/EarningsperShareNarrativeDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/AssetsandLiabilitiesatFairValue" xlink:type="simple" xlink:href="intl-20201231.xsd#AssetsandLiabilitiesatFairValue"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/AssetsandLiabilitiesatFairValue" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/AssetsandLiabilitiesatFairValueTables" xlink:type="simple" xlink:href="intl-20201231.xsd#AssetsandLiabilitiesatFairValueTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/AssetsandLiabilitiesatFairValueTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/AssetsandLiabilitiesatFairValueNarrativeDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#AssetsandLiabilitiesatFairValueNarrativeDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/AssetsandLiabilitiesatFairValueNarrativeDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/AssetsandLiabilitiesatFairValueFinancialAssetsandLiabilitiesMeasuredatFairValueDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#AssetsandLiabilitiesatFairValueFinancialAssetsandLiabilitiesMeasuredatFairValueDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/AssetsandLiabilitiesatFairValueFinancialAssetsandLiabilitiesMeasuredatFairValueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_26398719-d72b-46bf-b89f-5b9490cca3fa" 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_FinancialInstrumentsOwnedAtFairValue_25ab1cb4-7ff6-4e91-b440-e285bb98859f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancialInstrumentsOwnedAtFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_26398719-d72b-46bf-b89f-5b9490cca3fa" xlink:to="loc_us-gaap_FinancialInstrumentsOwnedAtFairValue_25ab1cb4-7ff6-4e91-b440-e285bb98859f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesFromClearingOrganizations_fab8ee28-07eb-4f5e-a6ee-268139a34520" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReceivablesFromClearingOrganizations"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_26398719-d72b-46bf-b89f-5b9490cca3fa" xlink:to="loc_us-gaap_ReceivablesFromClearingOrganizations_fab8ee28-07eb-4f5e-a6ee-268139a34520" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndSecuritiesSegregatedUnderFederalAndOtherRegulations_08abf087-f6a3-4deb-b450-ef5cff75f1e4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndSecuritiesSegregatedUnderFederalAndOtherRegulations"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_26398719-d72b-46bf-b89f-5b9490cca3fa" xlink:to="loc_us-gaap_CashAndSecuritiesSegregatedUnderFederalAndOtherRegulations_08abf087-f6a3-4deb-b450-ef5cff75f1e4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryGross_c398b6c6-ca9a-4353-b406-2b6e40f80472" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryGross"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_26398719-d72b-46bf-b89f-5b9490cca3fa" xlink:to="loc_us-gaap_InventoryGross_c398b6c6-ca9a-4353-b406-2b6e40f80472" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_869a1df3-d61d-49bb-b0ef-674d5bb0ca73" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_26398719-d72b-46bf-b89f-5b9490cca3fa" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_869a1df3-d61d-49bb-b0ef-674d5bb0ca73" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_18f46c92-ab17-4658-805b-bd1da580a29b" 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_FinancialInstrumentsSoldNotYetPurchasedAtFairValue_86ad6de7-86e7-4e69-8fa0-a63017426957" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosure_18f46c92-ab17-4658-805b-bd1da580a29b" xlink:to="loc_us-gaap_FinancialInstrumentsSoldNotYetPurchasedAtFairValue_86ad6de7-86e7-4e69-8fa0-a63017426957" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_PayablesToBrokerDealersAndClearingOrganizations_78a0dd7b-57dd-42fd-9ddd-704ce5dc3271" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_PayablesToBrokerDealersAndClearingOrganizations"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosure_18f46c92-ab17-4658-805b-bd1da580a29b" xlink:to="loc_srt_PayablesToBrokerDealersAndClearingOrganizations_78a0dd7b-57dd-42fd-9ddd-704ce5dc3271" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndOtherAccruedLiabilities_2a1a6f29-d785-45b0-8156-f0c3c718d020" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsPayableAndOtherAccruedLiabilities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosure_18f46c92-ab17-4658-805b-bd1da580a29b" xlink:to="loc_us-gaap_AccountsPayableAndOtherAccruedLiabilities_2a1a6f29-d785-45b0-8156-f0c3c718d020" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRisk" xlink:type="simple" xlink:href="intl-20201231.xsd#FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRisk"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRisk" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskTables" xlink:type="simple" xlink:href="intl-20201231.xsd#FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskNarrativeDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskNarrativeDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskNarrativeDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskGrossDerivativeAssetsandLiabilitiesbyTypeandBalanceSheetLocationDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskGrossDerivativeAssetsandLiabilitiesbyTypeandBalanceSheetLocationDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskGrossDerivativeAssetsandLiabilitiesbyTypeandBalanceSheetLocationDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskTBAsandForwardSettlingSecuritiesDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskTBAsandForwardSettlingSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskTBAsandForwardSettlingSecuritiesDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskRealizedGainsLossesonDerivativeContractsDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskRealizedGainsLossesonDerivativeContractsDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/FinancialInstrumentswithOffBalanceSheetRiskandConcentrationsofCreditRiskRealizedGainsLossesonDerivativeContractsDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/AllowanceforDoubtfulAccounts" xlink:type="simple" xlink:href="intl-20201231.xsd#AllowanceforDoubtfulAccounts"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/AllowanceforDoubtfulAccounts" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/AllowanceforDoubtfulAccountsTables" xlink:type="simple" xlink:href="intl-20201231.xsd#AllowanceforDoubtfulAccountsTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/AllowanceforDoubtfulAccountsTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/AllowanceforDoubtfulAccountsNarrativeDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#AllowanceforDoubtfulAccountsNarrativeDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/AllowanceforDoubtfulAccountsNarrativeDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/AllowanceforDoubtfulAccountsAllowanceforBadDebtsDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#AllowanceforDoubtfulAccountsAllowanceforBadDebtsDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/AllowanceforDoubtfulAccountsAllowanceforBadDebtsDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/PhysicalCommoditiesInventory" xlink:type="simple" xlink:href="intl-20201231.xsd#PhysicalCommoditiesInventory"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/PhysicalCommoditiesInventory" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/PhysicalCommoditiesInventoryTables" xlink:type="simple" xlink:href="intl-20201231.xsd#PhysicalCommoditiesInventoryTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/PhysicalCommoditiesInventoryTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/PhysicalCommoditiesInventoryPhysicalCommoditiesInventoryDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#PhysicalCommoditiesInventoryPhysicalCommoditiesInventoryDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/PhysicalCommoditiesInventoryPhysicalCommoditiesInventoryDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_c722d64c-3291-432c-9deb-3c700c24ba33" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AgriculturalRelatedInventory_c6a9bf42-f813-4a73-9279-8505b461f3b9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AgriculturalRelatedInventory"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_c722d64c-3291-432c-9deb-3c700c24ba33" xlink:to="loc_us-gaap_AgriculturalRelatedInventory_c6a9bf42-f813-4a73-9279-8505b461f3b9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_PhysicalCommoditiesInventoryAtFairValue_a99f084f-4479-4ce3-8d63-1b688a33cf90" xlink:href="intl-20201231.xsd#intl_PhysicalCommoditiesInventoryAtFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_c722d64c-3291-432c-9deb-3c700c24ba33" xlink:to="loc_intl_PhysicalCommoditiesInventoryAtFairValue_a99f084f-4479-4ce3-8d63-1b688a33cf90" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_b3a4e7cb-3407-4cba-a45f-791b82cfc0b1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_c722d64c-3291-432c-9deb-3c700c24ba33" xlink:to="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_b3a4e7cb-3407-4cba-a45f-791b82cfc0b1" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/PhysicalCommoditiesInventoryNarrativeDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#PhysicalCommoditiesInventoryNarrativeDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/PhysicalCommoditiesInventoryNarrativeDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/Goodwill" xlink:type="simple" xlink:href="intl-20201231.xsd#Goodwill"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/Goodwill" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/GoodwillTables" xlink:type="simple" xlink:href="intl-20201231.xsd#GoodwillTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/GoodwillTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/GoodwillGoodwillbySegmentDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#GoodwillGoodwillbySegmentDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/GoodwillGoodwillbySegmentDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/IntangibleAssets" xlink:type="simple" xlink:href="intl-20201231.xsd#IntangibleAssets"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/IntangibleAssets" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/IntangibleAssetsTables" xlink:type="simple" xlink:href="intl-20201231.xsd#IntangibleAssetsTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/IntangibleAssetsTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/IntangibleAssetsGrossandNetIntangibleAssetsbyMajorClassDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#IntangibleAssetsGrossandNetIntangibleAssetsbyMajorClassDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/IntangibleAssetsGrossandNetIntangibleAssetsbyMajorClassDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_fc75c36d-63e5-4f7a-b85d-580ee65f5921" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedComputerSoftwareGross_928f98a3-6a8c-49e8-b7aa-0af070bb8287" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CapitalizedComputerSoftwareGross"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_fc75c36d-63e5-4f7a-b85d-580ee65f5921" xlink:to="loc_us-gaap_CapitalizedComputerSoftwareGross_928f98a3-6a8c-49e8-b7aa-0af070bb8287" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_fb5fa3fd-568e-40e0-97be-97ee5abbc44b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_fc75c36d-63e5-4f7a-b85d-580ee65f5921" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_fb5fa3fd-568e-40e0-97be-97ee5abbc44b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_4a9a189f-02b2-493a-9ef8-23bf96b0eeae" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_b5d7450b-ffde-485c-a40c-e169864d4982" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_4a9a189f-02b2-493a-9ef8-23bf96b0eeae" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_b5d7450b-ffde-485c-a40c-e169864d4982" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_f9a689a4-97ed-4e15-84b9-e083641f16f5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_4a9a189f-02b2-493a-9ef8-23bf96b0eeae" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_f9a689a4-97ed-4e15-84b9-e083641f16f5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_af9c9fe7-1b22-447e-8fc0-3027a213615f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedLicenseAgreements_46e10441-c4c8-4d9d-9805-0273070aec3c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndefiniteLivedLicenseAgreements"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_af9c9fe7-1b22-447e-8fc0-3027a213615f" xlink:to="loc_us-gaap_IndefiniteLivedLicenseAgreements_46e10441-c4c8-4d9d-9805-0273070aec3c" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/IntangibleAssetsNarrativeDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#IntangibleAssetsNarrativeDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/IntangibleAssetsNarrativeDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/IntangibleAssetsFiniteLivedIntangibleAssetsFutureAmortizationExpenseDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#IntangibleAssetsFiniteLivedIntangibleAssetsFutureAmortizationExpenseDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/IntangibleAssetsFiniteLivedIntangibleAssetsFutureAmortizationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_7dfe47fc-9ae4-4533-84fa-89183beda69b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_9adeb84e-c5bf-418a-8afc-cc2d64880b2b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_7dfe47fc-9ae4-4533-84fa-89183beda69b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_9adeb84e-c5bf-418a-8afc-cc2d64880b2b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_e04ed6c1-e176-42e0-8856-483fe04c8066" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_7dfe47fc-9ae4-4533-84fa-89183beda69b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_e04ed6c1-e176-42e0-8856-483fe04c8066" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_d918f585-971b-4a5d-a9aa-eb1e170eb2ed" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_7dfe47fc-9ae4-4533-84fa-89183beda69b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_d918f585-971b-4a5d-a9aa-eb1e170eb2ed" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_d8dbe2fc-977f-4692-bfe4-e100df42d5c7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_7dfe47fc-9ae4-4533-84fa-89183beda69b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_d8dbe2fc-977f-4692-bfe4-e100df42d5c7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_a600ee92-926f-48e8-8a7c-506d6e822119" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_7dfe47fc-9ae4-4533-84fa-89183beda69b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_a600ee92-926f-48e8-8a7c-506d6e822119" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CreditFacilities" xlink:type="simple" xlink:href="intl-20201231.xsd#CreditFacilities"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CreditFacilities" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CreditFacilitiesTables" xlink:type="simple" xlink:href="intl-20201231.xsd#CreditFacilitiesTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CreditFacilitiesTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CreditFacilitiesNumberofCreditFacilitiesDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#CreditFacilitiesNumberofCreditFacilitiesDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CreditFacilitiesNumberofCreditFacilitiesDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CreditFacilitiesSeniorSecuredNotesDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#CreditFacilitiesSeniorSecuredNotesDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CreditFacilitiesSeniorSecuredNotesDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CreditFacilitiesCreditFacilitiesandFinancingBridgeCommitmentDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#CreditFacilitiesCreditFacilitiesandFinancingBridgeCommitmentDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CreditFacilitiesCreditFacilitiesandFinancingBridgeCommitmentDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactions" xlink:type="simple" xlink:href="intl-20201231.xsd#SecuritiesandCommodityFinancingTransactions"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactions" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactionsTables" xlink:type="simple" xlink:href="intl-20201231.xsd#SecuritiesandCommodityFinancingTransactionsTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactionsTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactionsNarrativeDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#SecuritiesandCommodityFinancingTransactionsNarrativeDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactionsNarrativeDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactionsCollateralMaturitiesofGrossObligationsDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#SecuritiesandCommodityFinancingTransactionsCollateralMaturitiesofGrossObligationsDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactionsCollateralMaturitiesofGrossObligationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralizedFinancings_001dc3a3-d435-4df7-ab56-6013ac1e2b80" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralizedFinancings"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_a867c27b-b721-4859-a074-502566394168" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchase"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CollateralizedFinancings_001dc3a3-d435-4df7-ab56-6013ac1e2b80" xlink:to="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_a867c27b-b721-4859-a074-502566394168" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesLoaned_8e2904a2-c9a6-450f-a84c-e91db921dde2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesLoaned"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CollateralizedFinancings_001dc3a3-d435-4df7-ab56-6013ac1e2b80" xlink:to="loc_us-gaap_SecuritiesLoaned_8e2904a2-c9a6-450f-a84c-e91db921dde2" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactionsUnderlyingCollateralTypesofGrossObligationsDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#SecuritiesandCommodityFinancingTransactionsUnderlyingCollateralTypesofGrossObligationsDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactionsUnderlyingCollateralTypesofGrossObligationsDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactionsNettingofSecuritiesPurchasedUnderAgreementsDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#SecuritiesandCommodityFinancingTransactionsNettingofSecuritiesPurchasedUnderAgreementsDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/SecuritiesandCommodityFinancingTransactionsNettingofSecuritiesPurchasedUnderAgreementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_260b6914-8c68-4410-ac4a-7d720e7aaff3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchase"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseGross_12b97edc-8a7d-4636-944e-6bab359864c4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseGross"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_260b6914-8c68-4410-ac4a-7d720e7aaff3" xlink:to="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseGross_12b97edc-8a7d-4636-944e-6bab359864c4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseAsset_32e133cb-664d-4bf1-877e-2bf875a23e56" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseAsset"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchase_260b6914-8c68-4410-ac4a-7d720e7aaff3" xlink:to="loc_us-gaap_SecuritiesSoldUnderAgreementsToRepurchaseAsset_32e133cb-664d-4bf1-877e-2bf875a23e56" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesPurchasedUnderAgreementsToResell_394405de-b740-4c41-91e2-fe625572e454" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesPurchasedUnderAgreementsToResell"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesPurchasedUnderAgreementsToResellLiability_3527ad91-3453-44fe-83aa-8fa7cf2a207d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesPurchasedUnderAgreementsToResellLiability"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_SecuritiesPurchasedUnderAgreementsToResell_394405de-b740-4c41-91e2-fe625572e454" xlink:to="loc_us-gaap_SecuritiesPurchasedUnderAgreementsToResellLiability_3527ad91-3453-44fe-83aa-8fa7cf2a207d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesPurchasedUnderAgreementsToResellGross_9b2ac8d2-888a-4a1e-a41c-2d79a7d6c0aa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesPurchasedUnderAgreementsToResellGross"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_SecuritiesPurchasedUnderAgreementsToResell_394405de-b740-4c41-91e2-fe625572e454" xlink:to="loc_us-gaap_SecuritiesPurchasedUnderAgreementsToResellGross_9b2ac8d2-888a-4a1e-a41c-2d79a7d6c0aa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesLoaned_4805d74e-f029-4cae-ad0a-ca8b357a16c6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesLoaned"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesLoanedGross_477f50df-4429-4050-bc42-b2f955fb6a95" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesLoanedGross"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_SecuritiesLoaned_4805d74e-f029-4cae-ad0a-ca8b357a16c6" xlink:to="loc_us-gaap_SecuritiesLoanedGross_477f50df-4429-4050-bc42-b2f955fb6a95" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesLoanedAsset_a8d68cc6-b722-4f12-ad2f-5ca9c7b61219" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesLoanedAsset"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_SecuritiesLoaned_4805d74e-f029-4cae-ad0a-ca8b357a16c6" xlink:to="loc_us-gaap_SecuritiesLoanedAsset_a8d68cc6-b722-4f12-ad2f-5ca9c7b61219" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesBorrowed_4e4fa18f-2d64-4370-bfbc-0faebc86441d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesBorrowed"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesBorrowedLiability_b32762ac-f019-4d9d-add4-c76a681e886f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesBorrowedLiability"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_SecuritiesBorrowed_4e4fa18f-2d64-4370-bfbc-0faebc86441d" xlink:to="loc_us-gaap_SecuritiesBorrowedLiability_b32762ac-f019-4d9d-add4-c76a681e886f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuritiesBorrowedGross_d6327a0c-5c9e-4104-9c09-8d84caf15b08" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SecuritiesBorrowedGross"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_SecuritiesBorrowed_4e4fa18f-2d64-4370-bfbc-0faebc86441d" xlink:to="loc_us-gaap_SecuritiesBorrowedGross_d6327a0c-5c9e-4104-9c09-8d84caf15b08" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CommitmentsandContingencies" xlink:type="simple" xlink:href="intl-20201231.xsd#CommitmentsandContingencies"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CommitmentsandContingencies" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CommitmentsandContingenciesDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#CommitmentsandContingenciesDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CommitmentsandContingenciesDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/AccumulatedOtherComprehensiveLossNet" xlink:type="simple" xlink:href="intl-20201231.xsd#AccumulatedOtherComprehensiveLossNet"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/AccumulatedOtherComprehensiveLossNet" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/AccumulatedOtherComprehensiveLossNetTables" xlink:type="simple" xlink:href="intl-20201231.xsd#AccumulatedOtherComprehensiveLossNetTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/AccumulatedOtherComprehensiveLossNetTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/AccumulatedOtherComprehensiveLossNetDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#AccumulatedOtherComprehensiveLossNetDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/AccumulatedOtherComprehensiveLossNetDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/RevenuefromContractswithClients" xlink:type="simple" xlink:href="intl-20201231.xsd#RevenuefromContractswithClients"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/RevenuefromContractswithClients" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/RevenuefromContractswithClientsTables" xlink:type="simple" xlink:href="intl-20201231.xsd#RevenuefromContractswithClientsTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/RevenuefromContractswithClientsTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/RevenuefromContractswithClientsNarrativeDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#RevenuefromContractswithClientsNarrativeDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/RevenuefromContractswithClientsNarrativeDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/RevenuefromContractswithClientsRevenuefromContractswithClientsDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#RevenuefromContractswithClientsRevenuefromContractswithClientsDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/RevenuefromContractswithClientsRevenuefromContractswithClientsDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/OtherExpenses" xlink:type="simple" xlink:href="intl-20201231.xsd#OtherExpenses"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/OtherExpenses" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/OtherExpensesTables" xlink:type="simple" xlink:href="intl-20201231.xsd#OtherExpensesTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/OtherExpensesTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/OtherExpensesOtherExpensesBreakoutDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#OtherExpensesOtherExpensesBreakoutDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/OtherExpensesOtherExpensesBreakoutDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoninterestExpense_80059196-0084-478b-95a1-86b7f520e7db" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNoninterestExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralInsuranceExpense_427a00c4-bc6e-4524-ac51-a9d43ab3cf29" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GeneralInsuranceExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherNoninterestExpense_80059196-0084-478b-95a1-86b7f520e7db" xlink:to="loc_us-gaap_GeneralInsuranceExpense_427a00c4-bc6e-4524-ac51-a9d43ab3cf29" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SuppliesAndPostageExpense_0e9bb38b-ec12-4ce4-bf78-8d1d829916b2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SuppliesAndPostageExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherNoninterestExpense_80059196-0084-478b-95a1-86b7f520e7db" xlink:to="loc_us-gaap_SuppliesAndPostageExpense_0e9bb38b-ec12-4ce4-bf78-8d1d829916b2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClearanceFees_eb5662a6-68cb-4972-8d5c-cdec8c37edeb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClearanceFees"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherNoninterestExpense_80059196-0084-478b-95a1-86b7f520e7db" xlink:to="loc_us-gaap_ClearanceFees_eb5662a6-68cb-4972-8d5c-cdec8c37edeb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxesExcludingIncomeAndExciseTaxes_a60b171d-a29e-4a6f-864c-a9c4801a02b5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TaxesExcludingIncomeAndExciseTaxes"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherNoninterestExpense_80059196-0084-478b-95a1-86b7f520e7db" xlink:to="loc_us-gaap_TaxesExcludingIncomeAndExciseTaxes_a60b171d-a29e-4a6f-864c-a9c4801a02b5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccretionExpense_365c4324-b7db-45c5-98e0-1e01c39bfb7a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccretionExpense"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherNoninterestExpense_80059196-0084-478b-95a1-86b7f520e7db" xlink:to="loc_us-gaap_AccretionExpense_365c4324-b7db-45c5-98e0-1e01c39bfb7a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherExpenses_335e9db3-0657-4769-8138-a601598589a3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherExpenses"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherNoninterestExpense_80059196-0084-478b-95a1-86b7f520e7db" xlink:to="loc_us-gaap_OtherExpenses_335e9db3-0657-4769-8138-a601598589a3" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/IncomeTaxes" xlink:type="simple" xlink:href="intl-20201231.xsd#IncomeTaxes"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/IncomeTaxes" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/IncomeTaxesDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#IncomeTaxesDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/IncomeTaxesDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CapitalandOtherRegulatoryRequirements" xlink:type="simple" xlink:href="intl-20201231.xsd#CapitalandOtherRegulatoryRequirements"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CapitalandOtherRegulatoryRequirements" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CapitalandOtherRegulatoryRequirementsTables" xlink:type="simple" xlink:href="intl-20201231.xsd#CapitalandOtherRegulatoryRequirementsTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CapitalandOtherRegulatoryRequirementsTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/CapitalandOtherRegulatoryRequirementsRegulatoryCapitalRequirementsDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#CapitalandOtherRegulatoryRequirementsRegulatoryCapitalRequirementsDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/CapitalandOtherRegulatoryRequirementsRegulatoryCapitalRequirementsDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/SegmentAnalysis" xlink:type="simple" xlink:href="intl-20201231.xsd#SegmentAnalysis"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/SegmentAnalysis" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/SegmentAnalysisTables" xlink:type="simple" xlink:href="intl-20201231.xsd#SegmentAnalysisTables"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/SegmentAnalysisTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/SegmentAnalysisNarrativeDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#SegmentAnalysisNarrativeDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/SegmentAnalysisNarrativeDetails" xlink:type="extended"/>
  <link:roleRef roleURI="http://www.intlfcstone.com/role/SegmentAnalysisSegmentReportingDetails" xlink:type="simple" xlink:href="intl-20201231.xsd#SegmentAnalysisSegmentReportingDetails"/>
  <link:calculationLink xlink:role="http://www.intlfcstone.com/role/SegmentAnalysisSegmentReportingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_52fe0d8d-ab57-4288-8474-6d6b6bf90d45" 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_OtherNonoperatingGainsLosses_4256ce9e-0093-42ce-bc2e-2534db28ef74" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherNonoperatingGainsLosses"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_52fe0d8d-ab57-4288-8474-6d6b6bf90d45" xlink:to="loc_us-gaap_OtherNonoperatingGainsLosses_4256ce9e-0093-42ce-bc2e-2534db28ef74" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_SegmentIncome_755a82ac-97b4-466e-a0ca-f8efed97f029" xlink:href="intl-20201231.xsd#intl_SegmentIncome"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_52fe0d8d-ab57-4288-8474-6d6b6bf90d45" xlink:to="loc_intl_SegmentIncome_755a82ac-97b4-466e-a0ca-f8efed97f029" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_intl_Costsnotallocatedtooperatingsegments_18cab0bd-58f6-4cf0-8cc1-579678082aeb" xlink:href="intl-20201231.xsd#intl_Costsnotallocatedtooperatingsegments"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_52fe0d8d-ab57-4288-8474-6d6b6bf90d45" xlink:to="loc_intl_Costsnotallocatedtooperatingsegments_18cab0bd-58f6-4cf0-8cc1-579678082aeb" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
