<?xml version="1.0" encoding="us-ascii"?>
<!--XBRL document created with Merrill Bridge  8.2.0.61 -->
<!--Based on XBRL 2.1-->
<!--Created on: 11/5/2018 5:22:21 PM-->
<!--Modified on: 11/5/2018 5:22:21 PM-->
<link:linkbase 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" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xlink="http://www.w3.org/1999/xlink">
  <roleRef xlink:type="simple" xlink:href="xncr-20180930.xsd#StatementBalanceSheets" roleURI="http://www.xencor.com/role/StatementBalanceSheets" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="xncr-20180930.xsd#StatementStatementsOfComprehensiveIncomeLoss" roleURI="http://www.xencor.com/role/StatementStatementsOfComprehensiveIncomeLoss" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="xncr-20180930.xsd#StatementStatementsOfCashFlows" roleURI="http://www.xencor.com/role/StatementStatementsOfCashFlows" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="xncr-20180930.xsd#DisclosureFairValueOfFinancialInstrumentsDetails" roleURI="http://www.xencor.com/role/DisclosureFairValueOfFinancialInstrumentsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="xncr-20180930.xsd#DisclosureMarketableSecuritiesDetails" roleURI="http://www.xencor.com/role/DisclosureMarketableSecuritiesDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="xncr-20180930.xsd#DisclosureMarketableSecuritiesMaturitiesDetails" roleURI="http://www.xencor.com/role/DisclosureMarketableSecuritiesMaturitiesDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="xncr-20180930.xsd#DisclosurePriorPeriodFinancialStatementsComprehensiveIncomeLossDetails" roleURI="http://www.xencor.com/role/DisclosurePriorPeriodFinancialStatementsComprehensiveIncomeLossDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <roleRef xlink:type="simple" xlink:href="xncr-20180930.xsd#DisclosurePriorPeriodFinancialStatementsCashFlowsDetails" roleURI="http://www.xencor.com/role/DisclosurePriorPeriodFinancialStatementsCashFlowsDetails" xmlns="http://www.xbrl.org/2003/linkbase" />
  <calculationLink xlink:role="http://www.xencor.com/role/StatementBalanceSheets" xlink:type="extended" xlink:title="00100 - Statement - Balance Sheets" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Assets" xlink:label="Assets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent_636770353401551212" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="us-gaap_AssetsCurrent_636770353401551212" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_636770353401551212" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_636770353401651210" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_636770353401551212" xlink:to="us-gaap_AccountsReceivableNetCurrent_636770353401651210" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="us-gaap_MarketableSecuritiesCurrent_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_636770353401551212" xlink:to="us-gaap_MarketableSecuritiesCurrent_636770353401651210" order="3" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxesReceivable" xlink:label="us-gaap_IncomeTaxesReceivable_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_636770353401551212" xlink:to="us-gaap_IncomeTaxesReceivable_636770353401651210" order="4" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AssetsCurrent_636770353401551212" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_636770353401651210" order="5" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_636770353401651210" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill_636770353401651210" order="3" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MarketableSecuritiesNoncurrent" xlink:label="us-gaap_MarketableSecuritiesNoncurrent_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="us-gaap_MarketableSecuritiesNoncurrent_636770353401651210" order="4" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxesReceivableNoncurrent" xlink:label="us-gaap_IncomeTaxesReceivableNoncurrent_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="us-gaap_IncomeTaxesReceivableNoncurrent_636770353401651210" order="5" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NotesAndLoansReceivableNetNoncurrent" xlink:label="us-gaap_NotesAndLoansReceivableNetNoncurrent_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="us-gaap_NotesAndLoansReceivableNetNoncurrent_636770353401651210" order="6" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestReceivableNoncurrent" xlink:label="us-gaap_InterestReceivableNoncurrent_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="us-gaap_InterestReceivableNoncurrent_636770353401651210" order="7" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="us-gaap_OtherAssetsNoncurrent_636770353401651210" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="us-gaap_OtherAssetsNoncurrent_636770353401651210" order="8" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="LiabilitiesAndStockholdersEquity" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_Liabilities_636770353401751208" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities_636770353401751208" xlink:to="us-gaap_LiabilitiesCurrent_636770353401751208" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="us-gaap_AccountsPayableCurrent_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent_636770353401751208" xlink:to="us-gaap_AccountsPayableCurrent_636770353401751208" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent_636770353401751208" xlink:to="us-gaap_AccruedLiabilitiesCurrent_636770353401751208" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCurrent" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent_636770353401751208" xlink:to="us-gaap_ContractWithCustomerLiabilityCurrent_636770353401751208" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredRentCreditCurrent" xlink:label="us-gaap_DeferredRentCreditCurrent_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent_636770353401751208" xlink:to="us-gaap_DeferredRentCreditCurrent_636770353401751208" order="4" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_TaxesPayableCurrent" xlink:label="us-gaap_TaxesPayableCurrent_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesCurrent_636770353401751208" xlink:to="us-gaap_TaxesPayableCurrent_636770353401751208" order="5" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent" xlink:label="us-gaap_ContractWithCustomerLiabilityNoncurrent_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities_636770353401751208" xlink:to="us-gaap_ContractWithCustomerLiabilityNoncurrent_636770353401751208" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DeferredRentCreditNoncurrent" xlink:label="us-gaap_DeferredRentCreditNoncurrent_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities_636770353401751208" xlink:to="us-gaap_DeferredRentCreditNoncurrent_636770353401751208" order="3" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_StockholdersEquity_636770353401751208" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_636770353401751208" xlink:to="us-gaap_CommonStockValue_636770353401751208" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_636770353401751208" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_636770353401751208" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_636770353401751208" xlink:to="us-gaap_AdditionalPaidInCapital_636770353401751208" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity_636770353401751208" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_636770353401751208" order="4" use="optional" weight="1" />
  </calculationLink>
  <calculationLink xlink:role="http://www.xencor.com/role/StatementStatementsOfComprehensiveIncomeLoss" xlink:type="extended" xlink:title="00200 - Statement - Statements of Comprehensive Income (Loss)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="ComprehensiveIncomeNetOfTax" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_MarketableSecuritiesUnrealizedGainLoss" xlink:label="us-gaap_MarketableSecuritiesUnrealizedGainLoss_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_MarketableSecuritiesUnrealizedGainLoss_636770353401751208" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_NetIncomeLoss_636770353401751208" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss_636770353401751208" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_636770353401751208" order="1" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_636770353401751208" xlink:to="us-gaap_OperatingIncomeLoss_636770353401751208" order="1" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss_636770353401751208" xlink:to="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_636770353401751208" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="us-gaap_OperatingExpenses_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingIncomeLoss_636770353401751208" xlink:to="us-gaap_OperatingExpenses_636770353401751208" order="2" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="us-gaap_ResearchAndDevelopmentExpense_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingExpenses_636770353401751208" xlink:to="us-gaap_ResearchAndDevelopmentExpense_636770353401751208" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="us-gaap_GeneralAndAdministrativeExpense_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OperatingExpenses_636770353401751208" xlink:to="us-gaap_GeneralAndAdministrativeExpense_636770353401751208" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_636770353401751208" xlink:to="us-gaap_NonoperatingIncomeExpense_636770353401751208" order="2" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestIncomeExpenseNet" xlink:label="us-gaap_InterestIncomeExpenseNet_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense_636770353401751208" xlink:to="us-gaap_InterestIncomeExpenseNet_636770353401751208" order="1" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense_636770353401751208" xlink:to="us-gaap_OtherNonoperatingIncomeExpense_636770353401751208" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss_636770353401751208" xlink:to="us-gaap_IncomeTaxExpenseBenefit_636770353401751208" order="2" use="optional" weight="-1" priority="2" />
  </calculationLink>
  <calculationLink xlink:role="http://www.xencor.com/role/StatementStatementsOfCashFlows" xlink:type="extended" xlink:title="00400 - Statement - Statements of Cash Flows" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProfitLoss" xlink:label="us-gaap_ProfitLoss_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_ProfitLoss_636770353401751208" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_DepreciationDepletionAndAmortization_636770353401751208" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:label="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_636770353401751208" order="3" use="optional" weight="-1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_ShareBasedCompensation_636770353401751208" order="4" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NoncashProjectAbandonmentCosts" xlink:label="us-gaap_NoncashProjectAbandonmentCosts_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_NoncashProjectAbandonmentCosts_636770353401751208" order="5" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_GainLossOnDispositionOfAssets1" xlink:label="us-gaap_GainLossOnDispositionOfAssets1_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_GainLossOnDispositionOfAssets1_636770353401751208" order="6" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable" xlink:label="us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_636770353401751208" order="7" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables" xlink:label="us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables_636770353401751208" order="8" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedInvestmentIncomeReceivable" xlink:label="us-gaap_IncreaseDecreaseInAccruedInvestmentIncomeReceivable_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_IncreaseDecreaseInAccruedInvestmentIncomeReceivable_636770353401751208" order="9" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_636770353401751208" order="10" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable_636770353401751208" order="11" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities_636770353401751208" order="12" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="xncr-20180930.xsd#xncr_IncreaseDecreaseInDeferredRent" xlink:label="xncr_IncreaseDecreaseInDeferredRent_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="xncr_IncreaseDecreaseInDeferredRent_636770353401751208" order="13" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability" xlink:label="us-gaap_IncreaseDecreaseInContractWithCustomerLiability_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities_636770353401751208" xlink:to="us-gaap_IncreaseDecreaseInContractWithCustomerLiability_636770353401751208" order="14" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_636770353401751208" order="2" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireMarketableSecurities" xlink:label="us-gaap_PaymentsToAcquireMarketableSecurities_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities_636770353401751208" xlink:to="us-gaap_PaymentsToAcquireMarketableSecurities_636770353401751208" order="1" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireIntangibleAssets" xlink:label="us-gaap_PaymentsToAcquireIntangibleAssets_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities_636770353401751208" xlink:to="us-gaap_PaymentsToAcquireIntangibleAssets_636770353401751208" order="2" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities_636770353401751208" xlink:to="us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_636770353401751208" order="3" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsForProceedsFromProductiveAssets" xlink:label="us-gaap_PaymentsForProceedsFromProductiveAssets_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities_636770353401751208" xlink:to="us-gaap_PaymentsForProceedsFromProductiveAssets_636770353401751208" order="4" use="optional" weight="-1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsForProceedsFromLoansReceivable" xlink:label="us-gaap_PaymentsForProceedsFromLoansReceivable_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities_636770353401751208" xlink:to="us-gaap_PaymentsForProceedsFromLoansReceivable_636770353401751208" order="5" use="optional" weight="-1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_636770353401751208" order="3" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions" xlink:label="us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_636770353401751208" xlink:to="us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_636770353401751208" order="1" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsOfStockIssuanceCosts" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_636770353401751208" xlink:to="us-gaap_PaymentsOfStockIssuanceCosts_636770353401751208" order="2" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromStockPlans" xlink:label="us-gaap_ProceedsFromStockPlans_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_636770353401751208" xlink:to="us-gaap_ProceedsFromStockPlans_636770353401751208" order="3" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities_636770353401751208" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock_636770353401751208" order="4" use="optional" weight="1" priority="2" />
  </calculationLink>
  <calculationLink xlink:role="http://www.xencor.com/role/DisclosureFairValueOfFinancialInstrumentsDetails" xlink:type="extended" xlink:title="40201 - Disclosure - Fair Value of Financial Instruments (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="AssetsFairValueDisclosure" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsFairValueDisclosure" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_636770353401751208" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsFairValueDisclosure" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtSecurities_636770353401751208" order="2" use="optional" weight="1" priority="2" />
  </calculationLink>
  <calculationLink xlink:role="http://www.xencor.com/role/DisclosureMarketableSecuritiesDetails" xlink:type="extended" xlink:title="40501 - Disclosure - Marketable Securities (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_636770353401751208" order="1" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:to="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_636770353401751208" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtSecurities_636770353401751208" order="3" use="optional" weight="1" priority="2" />
  </calculationLink>
  <calculationLink xlink:role="http://www.xencor.com/role/DisclosureMarketableSecuritiesMaturitiesDetails" xlink:type="extended" xlink:title="40502 - Disclosure - Marketable Securities - Maturities (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities" xlink:label="AvailableForSaleSecuritiesDebtSecurities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AvailableForSaleSecuritiesDebtSecurities" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_636770353401751208" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AvailableForSaleSecuritiesDebtSecurities" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_636770353401751208" order="2" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:label="AvailableForSaleDebtSecuritiesAmortizedCostBasis" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_636770353401751208" order="1" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AvailableForSaleDebtSecuritiesAmortizedCostBasis" xlink:to="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_636770353401751208" order="2" use="optional" weight="1" priority="2" />
  </calculationLink>
  <calculationLink xlink:role="http://www.xencor.com/role/DisclosurePriorPeriodFinancialStatementsComprehensiveIncomeLossDetails" xlink:type="extended" xlink:title="41104 - Disclosure - Prior-Period Financial Statements - Comprehensive Income (Loss) (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestExpense" xlink:label="us-gaap_InterestExpense_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_InterestExpense_636770353401751208" order="1" use="optional" weight="-1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_InterestIncomeOther" xlink:label="us-gaap_InterestIncomeOther_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_InterestIncomeOther_636770353401751208" order="2" use="optional" weight="1" priority="3" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_OtherNonoperatingIncomeExpense_636770353401751208" order="3" use="optional" weight="1" priority="2" />
  </calculationLink>
  <calculationLink xlink:role="http://www.xencor.com/role/DisclosurePriorPeriodFinancialStatementsCashFlowsDetails" xlink:type="extended" xlink:title="41106 - Disclosure - Prior-Period Financial Statements - Cash Flows (Details)" xmlns="http://www.xbrl.org/2003/linkbase">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireMarketableSecurities" xlink:label="us-gaap_PaymentsToAcquireMarketableSecurities_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_PaymentsToAcquireMarketableSecurities_636770353401751208" order="1" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquireIntangibleAssets" xlink:label="us-gaap_PaymentsToAcquireIntangibleAssets_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_PaymentsToAcquireIntangibleAssets_636770353401751208" order="2" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_636770353401751208" order="3" use="optional" weight="-1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_636770353401751208" order="4" use="optional" weight="1" priority="2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2018/elts/us-gaap-2018-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_636770353401751208" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_636770353401751208" order="5" use="optional" weight="1" priority="2" />
  </calculationLink>
</link:linkbase>
