<?xml version="1.0" encoding="us-ascii" standalone="no"?>
<!--Extended XBRL Calculation Linkbase Created with Tagger by RR Donnelley version 10.0.0.240-->
<!--Based on XBRL 2.1-->
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#BalanceSheets" roleURI="http://fbvirginia.com/role/BalanceSheets" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#StatementsOfComprehensiveIncomeLoss" roleURI="http://fbvirginia.com/role/StatementsOfComprehensiveIncomeLoss" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#StatementsOfCashFlows" roleURI="http://fbvirginia.com/role/StatementsOfCashFlows" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#SecuritiesTables" roleURI="http://fbvirginia.com/role/SecuritiesTables" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#LoansTables" roleURI="http://fbvirginia.com/role/LoansTables" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#AllowanceForLoanLossesTables" roleURI="http://fbvirginia.com/role/AllowanceForLoanLossesTables" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#BenefitPlansTables" roleURI="http://fbvirginia.com/role/BenefitPlansTables" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#FairValueMeasurementsTables" roleURI="http://fbvirginia.com/role/FairValueMeasurementsTables" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#SecuritiesDetails" roleURI="http://fbvirginia.com/role/SecuritiesDetails" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#SecuritiesDetails1" roleURI="http://fbvirginia.com/role/SecuritiesDetails1" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#SecuritiesDetailsTextual" roleURI="http://fbvirginia.com/role/SecuritiesDetailsTextual" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#LoansDetails" roleURI="http://fbvirginia.com/role/LoansDetails" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#LoansDetails1" roleURI="http://fbvirginia.com/role/LoansDetails1" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#LoansDetails2" roleURI="http://fbvirginia.com/role/LoansDetails2" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#LoansDetailsTextual" roleURI="http://fbvirginia.com/role/LoansDetailsTextual" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#AllowanceForLoanLossesDetails" roleURI="http://fbvirginia.com/role/AllowanceForLoanLossesDetails" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#AllowanceForLoanLossesDetails1" roleURI="http://fbvirginia.com/role/AllowanceForLoanLossesDetails1" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#AllowanceForLoanLossesDetails2" roleURI="http://fbvirginia.com/role/AllowanceForLoanLossesDetails2" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#AllowanceForLoanLossesDetailsTextual" roleURI="http://fbvirginia.com/role/AllowanceForLoanLossesDetailsTextual" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#TrustPreferredCapitalNotesDetailsTextual" roleURI="http://fbvirginia.com/role/TrustPreferredCapitalNotesDetailsTextual" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#BenefitPlansDetails" roleURI="http://fbvirginia.com/role/BenefitPlansDetails" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#BenefitPlansDetailsTextual" roleURI="http://fbvirginia.com/role/BenefitPlansDetailsTextual" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#FairValueMeasurementsDetails" roleURI="http://fbvirginia.com/role/FairValueMeasurementsDetails" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#FairValueMeasurementsDetails1" roleURI="http://fbvirginia.com/role/FairValueMeasurementsDetails1" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#FairValueMeasurementsDetails2" roleURI="http://fbvirginia.com/role/FairValueMeasurementsDetails2" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#FairValueMeasurementsDetails3" roleURI="http://fbvirginia.com/role/FairValueMeasurementsDetails3" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#FairValueMeasurementsDetails4" roleURI="http://fbvirginia.com/role/FairValueMeasurementsDetails4" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#BalanceSheetsParenthetical" roleURI="http://fbvirginia.com/role/BalanceSheetsParenthetical" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#StatementsOfChangesInShareholdersEquity" roleURI="http://fbvirginia.com/role/StatementsOfChangesInShareholdersEquity" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#Securities" roleURI="http://fbvirginia.com/role/Securities" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#Loans" roleURI="http://fbvirginia.com/role/Loans" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#AllowanceForLoanLosses" roleURI="http://fbvirginia.com/role/AllowanceForLoanLosses" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#OtherBorrowings" roleURI="http://fbvirginia.com/role/OtherBorrowings" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#TrustPreferredCapitalNotes" roleURI="http://fbvirginia.com/role/TrustPreferredCapitalNotes" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#BenefitPlans" roleURI="http://fbvirginia.com/role/BenefitPlans" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#FairValueMeasurements" roleURI="http://fbvirginia.com/role/FairValueMeasurements" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#CapitalPurchaseProgram" roleURI="http://fbvirginia.com/role/CapitalPurchaseProgram" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#CapitalPurchaseProgramDetails" roleURI="http://fbvirginia.com/role/CapitalPurchaseProgramDetails" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#SecuritiesDetail2" roleURI="http://fbvirginia.com/role/SecuritiesDetail2" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#OtherBorrowingsDetailsTextual" roleURI="http://fbvirginia.com/role/OtherBorrowingsDetailsTextual" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#OtherRealEstateOwned" roleURI="http://fbvirginia.com/role/OtherRealEstateOwned" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#AccumulatedOtherComprehensiveIncome" roleURI="http://fbvirginia.com/role/AccumulatedOtherComprehensiveIncome" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#OtherRealEstateOwnedTables" roleURI="http://fbvirginia.com/role/OtherRealEstateOwnedTables" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#OtherRealEstateOwnedDetails" roleURI="http://fbvirginia.com/role/OtherRealEstateOwnedDetails" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#OtherRealEstateOwnedDetails1" roleURI="http://fbvirginia.com/role/OtherRealEstateOwnedDetails1" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#OtherRealEstateOwnedDetailsTextual" roleURI="http://fbvirginia.com/role/OtherRealEstateOwnedDetailsTextual" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#AccumulatedOtherComprehensiveIncomeTables" roleURI="http://fbvirginia.com/role/AccumulatedOtherComprehensiveIncomeTables" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#AccumulatedOtherComprehensiveIncomeDetails" roleURI="http://fbvirginia.com/role/AccumulatedOtherComprehensiveIncomeDetails" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#StatementsOfComprehensiveIncomeLossParenthetical" roleURI="http://fbvirginia.com/role/StatementsOfComprehensiveIncomeLossParenthetical" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#DocumentAndEntityInformation" roleURI="http://fbvirginia.com/role/DocumentAndEntityInformation" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#GeneralPolicies" roleURI="http://fbvirginia.com/role/GeneralPolicies" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#General" roleURI="http://fbvirginia.com/role/General" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#CapitalRequirements" roleURI="http://fbvirginia.com/role/CapitalRequirements" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#EarningsPerCommonShare" roleURI="http://fbvirginia.com/role/EarningsPerCommonShare" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#CapitalRequirementsDetails" roleURI="http://fbvirginia.com/role/CapitalRequirementsDetails" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#CapitalRequirementsTables" roleURI="http://fbvirginia.com/role/CapitalRequirementsTables" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#CapitalRequirementsDetailsTextual" roleURI="http://fbvirginia.com/role/CapitalRequirementsDetailsTextual" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#EarningsPerCommonShareDetails" roleURI="http://fbvirginia.com/role/EarningsPerCommonShareDetails" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#StatementsOfIncome" roleURI="http://fbvirginia.com/role/StatementsOfIncome" />
  <roleRef xlink:type="simple" xlink:href="fxnc-20130331.xsd#StatementsOfIncomeParenthetical" roleURI="http://fbvirginia.com/role/StatementsOfIncomeParenthetical" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/BalanceSheets" xlink:title="0110 - Statement - Consolidated Balance Sheets">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_Liabilities" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_Deposits" xlink:label="us-gaap_Deposits" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Deposits" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NoninterestBearingDepositLiabilities" xlink:label="us-gaap_NoninterestBearingDepositLiabilities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Deposits" xlink:to="us-gaap_NoninterestBearingDepositLiabilities" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_TimeDeposits" xlink:label="us-gaap_TimeDeposits" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Deposits" xlink:to="us-gaap_TimeDeposits" order="60" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherBorrowings" xlink:label="us-gaap_OtherBorrowings" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_OtherBorrowings" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherLiabilities" xlink:label="us-gaap_OtherLiabilities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_OtherLiabilities" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_StockholdersEquity" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_PreferredStockValue" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_CommonStockValue" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="us-gaap_AdditionalPaidInCapital" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_AdditionalPaidInCapital" order="60" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" order="100" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CashAndDueFromBanks" xlink:label="us-gaap_CashAndDueFromBanks" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_CashAndDueFromBanks" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestBearingDepositsInBanks" xlink:label="us-gaap_InterestBearingDepositsInBanks" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_InterestBearingDepositsInBanks" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="us-gaap_AvailableForSaleSecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_AvailableForSaleSecurities" order="60" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RestrictedInvestments" xlink:label="us-gaap_RestrictedInvestments" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_RestrictedInvestments" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LoansReceivableHeldForSaleNet" xlink:label="us-gaap_LoansReceivableHeldForSaleNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_LoansReceivableHeldForSaleNet" order="100" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LoansAndLeasesReceivableNetReportedAmount" xlink:label="us-gaap_LoansAndLeasesReceivableNetReportedAmount" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_LoansAndLeasesReceivableNetReportedAmount" order="120" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" order="140" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestReceivable" xlink:label="us-gaap_InterestReceivable" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_InterestReceivable" order="160" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherAssets" xlink:label="us-gaap_OtherAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_OtherAssets" order="200" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DepositsSavingsDeposits" xlink:label="us-gaap_DepositsSavingsDeposits" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Deposits" xlink:to="us-gaap_DepositsSavingsDeposits" order="10" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherRealEstateAndForeclosedAssets" xlink:label="us-gaap_OtherRealEstateAndForeclosedAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_OtherRealEstateAndForeclosedAssets" order="10" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_JuniorSubordinatedNotes" xlink:label="us-gaap_JuniorSubordinatedNotes" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_JuniorSubordinatedNotes" order="10" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_BankOwnedLifeInsurance" xlink:label="us-gaap_BankOwnedLifeInsurance" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_Assets" xlink:to="us-gaap_BankOwnedLifeInsurance" order="180" use="optional" weight="1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/StatementsOfComprehensiveIncomeLoss" xlink:title="0130 - Statement - Consolidated Statements of Comprehensive Income (Loss) (Unaudited)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_ComprehensiveIncomeNetOfTax" xlink:to="us-gaap_NetIncomeLoss" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax" xlink:label="us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:to="us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax" order="10" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentForSaleOfSecuritiesIncludedInNetIncomeBeforeTax" xlink:label="loc_OtherComprehensiveIncomeLossReclassificationAdjustmentForSaleOfSecuritiesIncludedInNetIncomeBeforeTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent" xlink:to="loc_OtherComprehensiveIncomeLossReclassificationAdjustmentForSaleOfSecuritiesIncludedInNetIncomeBeforeTax" order="5" use="optional" weight="1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/StatementsOfCashFlows" xlink:title="0140 - Statement - Consolidated Statements of Cash Flows (Unaudited)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DepreciationAmortizationAndAccretionNet" xlink:label="us-gaap_DepreciationAmortizationAndAccretionNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_DepreciationAmortizationAndAccretionNet" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_GainLossOnSalesOfLoansNet" xlink:label="us-gaap_GainLossOnSalesOfLoansNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_GainLossOnSalesOfLoansNet" order="40" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RealEstateOwnedValuationAllowanceProvision" xlink:label="us-gaap_RealEstateOwnedValuationAllowanceProvision" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_RealEstateOwnedValuationAllowanceProvision" order="60" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses" xlink:label="us-gaap_ProvisionForLoanLeaseAndOtherLosses" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_ProvisionForLoanLeaseAndOtherLosses" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_GainsLossesOnSalesOfOtherRealEstate" xlink:label="us-gaap_GainsLossesOnSalesOfOtherRealEstate" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_GainsLossesOnSalesOfOtherRealEstate" order="100" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:label="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" order="120" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_GainLossOnSaleOfSecuritiesNet" xlink:label="us-gaap_GainLossOnSaleOfSecuritiesNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_GainLossOnSaleOfSecuritiesNet" order="140" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet" xlink:label="us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInAccruedInterestReceivableNet" order="160" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingAssets" order="180" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetIncomeLoss" order="200" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities" order="220" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale" xlink:label="us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_PaymentsForOriginationAndPurchasesOfLoansHeldForSale" order="240" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProceedsFromSaleOfLoansHeldForSale" xlink:label="us-gaap_ProceedsFromSaleOfLoansHeldForSale" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_ProceedsFromSaleOfLoansHeldForSale" order="260" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities" xlink:label="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecurities" xlink:label="us-gaap_PaymentsToAcquireAvailableForSaleSecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_PaymentsToAcquireAvailableForSaleSecurities" order="60" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PaymentsToAcquireProductiveAssets" xlink:label="us-gaap_PaymentsToAcquireProductiveAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_PaymentsToAcquireProductiveAssets" order="80" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProceedsFromSaleOfOtherRealEstate" xlink:label="us-gaap_ProceedsFromSaleOfOtherRealEstate" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_ProceedsFromSaleOfOtherRealEstate" order="100" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PaymentsForProceedsFromLoansAndLeases" xlink:label="us-gaap_PaymentsForProceedsFromLoansAndLeases" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_PaymentsForProceedsFromLoansAndLeases" order="120" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities" xlink:label="us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities" order="140" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities" order="60" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_IncreaseDecreaseInDeposits" xlink:label="us-gaap_IncreaseDecreaseInDeposits" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_IncreaseDecreaseInDeposits" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_IncreaseDecreaseInTimeDeposits" xlink:label="us-gaap_IncreaseDecreaseInTimeDeposits" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_IncreaseDecreaseInTimeDeposits" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RepaymentsOfOtherDebt" xlink:label="us-gaap_RepaymentsOfOtherDebt" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_RepaymentsOfOtherDebt" order="80" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" xlink:label="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock" order="120" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="fxnc-20130331.xsd#fxnc_ProceedsFromRedemptionOfRestrictedSecurities" xlink:label="fxnc_ProceedsFromRedemptionOfRestrictedSecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="fxnc_ProceedsFromRedemptionOfRestrictedSecurities" order="160" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" order="110" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_BankOwnedLifeInsuranceIncome" xlink:label="us-gaap_BankOwnedLifeInsuranceIncome" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_BankOwnedLifeInsuranceIncome" order="110" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_GainLossOnDispositionOfProperty" xlink:label="us-gaap_GainLossOnDispositionOfProperty" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_GainLossOnDispositionOfProperty" order="105" use="optional" weight="-1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/SecuritiesTables" xlink:title="0502 - Disclosure - Securities (Tables)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/LoansTables" xlink:title="0503 - Disclosure - Loans (Tables)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/AllowanceForLoanLossesTables" xlink:title="0504 - Disclosure - Allowance for Loan Losses (Tables)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/BenefitPlansTables" xlink:title="0509 - Disclosure - Benefit Plans (Tables)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/FairValueMeasurementsTables" xlink:title="0511 - Disclosure - Fair Value Measurements (Tables)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/SecuritiesDetails" xlink:title="0602 - Disclosure - Securities (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_AvailableForSaleSecurities" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLosses1" xlink:label="loc_AvailableForSaleSecuritiesGrossUnrealizedLosses1" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AvailableForSaleSecurities" xlink:to="loc_AvailableForSaleSecuritiesGrossUnrealizedLosses1" order="60" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AvailableforsaleSecuritiesGrossUnrealizedGain" xlink:label="loc_AvailableforsaleSecuritiesGrossUnrealizedGain" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AvailableForSaleSecurities" xlink:to="loc_AvailableforsaleSecuritiesGrossUnrealizedGain" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAmortizedCost" xlink:label="loc_AvailableForSaleSecuritiesAmortizedCost" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AvailableForSaleSecurities" xlink:to="loc_AvailableForSaleSecuritiesAmortizedCost" order="20" use="optional" weight="1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/SecuritiesDetails1" xlink:title="06021 - Disclosure - Securities (Details 1)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue" xlink:label="loc_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue" xlink:label="loc_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue" xlink:to="loc_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue" xlink:label="loc_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue" xlink:to="loc_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AvailableforsaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses2" xlink:label="loc_AvailableforsaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses2" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AvailableforsaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses2" xlink:label="loc_AvailableforsaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses2" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AvailableforsaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses2" xlink:to="loc_AvailableforsaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses2" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AvailableforsaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses2" xlink:label="loc_AvailableforsaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses2" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AvailableforsaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses2" xlink:to="loc_AvailableforsaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses2" order="20" use="optional" weight="1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/SecuritiesDetailsTextual" xlink:title="06023 - Disclosure - Securities (Details Textual)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/LoansDetails" xlink:title="0603 - Disclosure - Loans (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LoansAndLeasesReceivableNetReportedAmount" xlink:label="us-gaap_LoansAndLeasesReceivableNetReportedAmount" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LoansAndLeasesReceivableAllowance" xlink:label="loc_LoansAndLeasesReceivableAllowance" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LoansAndLeasesReceivableNetReportedAmount" xlink:to="loc_LoansAndLeasesReceivableAllowance" order="40" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LoansAndLeasesReceivableGrossCarryingAmount" xlink:label="loc_LoansAndLeasesReceivableGrossCarryingAmount" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_LoansAndLeasesReceivableNetReportedAmount" xlink:to="loc_LoansAndLeasesReceivableGrossCarryingAmount" order="20" use="optional" weight="1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/LoansDetails1" xlink:title="06031 - Disclosure - Loans (Details 1)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LoansAndLeasesReceivableGrossCarryingAmount" xlink:label="loc_LoansAndLeasesReceivableGrossCarryingAmount" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestmentCurrent" xlink:label="loc_FinancingReceivableRecordedInvestmentCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_LoansAndLeasesReceivableGrossCarryingAmount" xlink:to="loc_FinancingReceivableRecordedInvestmentCurrent" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestmentPastDue" xlink:label="loc_FinancingReceivableRecordedInvestmentPastDue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_LoansAndLeasesReceivableGrossCarryingAmount" xlink:to="loc_FinancingReceivableRecordedInvestmentPastDue" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue" xlink:label="loc_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_FinancingReceivableRecordedInvestmentPastDue" xlink:to="loc_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue" xlink:label="loc_FinancingReceivableRecordedInvestment60To89DaysPastDue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_FinancingReceivableRecordedInvestmentPastDue" xlink:to="loc_FinancingReceivableRecordedInvestment60To89DaysPastDue" order="10" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue" xlink:label="loc_FinancingReceivableRecordedInvestment30To59DaysPastDue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_FinancingReceivableRecordedInvestmentPastDue" xlink:to="loc_FinancingReceivableRecordedInvestment30To59DaysPastDue" order="5" use="optional" weight="1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/LoansDetails2" xlink:title="06032 - Disclosure - Loans (Details 2)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/LoansDetailsTextual" xlink:title="06033 - Disclosure - Loans (Details Textual)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/AllowanceForLoanLossesDetails" xlink:title="0604 - Disclosure - Allowance for Loan Losses (Details)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/AllowanceForLoanLossesDetails1" xlink:title="06041 - Disclosure - Allowance for Loan Losses (Details 1)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/AllowanceForLoanLossesDetails2" xlink:title="06042 - Disclosure - Allowance for Loan Losses (Details 2)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/AllowanceForLoanLossesDetailsTextual" xlink:title="06043 - Disclosure - Allowance for Loan Losses (Details Textual)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/TrustPreferredCapitalNotesDetailsTextual" xlink:title="0608 - Disclosure - Trust Preferred Capital Notes (Details)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/BenefitPlansDetails" xlink:title="0609 - Disclosure - Benefit Plans (Details)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:label="loc_DefinedBenefitPlanNetPeriodicBenefitCost" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="loc_DefinedBenefitPlanServiceCost" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:to="loc_DefinedBenefitPlanServiceCost" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="loc_DefinedBenefitPlanInterestCost" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:to="loc_DefinedBenefitPlanInterestCost" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:label="loc_DefinedBenefitPlanExpectedReturnOnPlanAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:to="loc_DefinedBenefitPlanExpectedReturnOnPlanAssets" order="60" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit" xlink:label="loc_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:to="loc_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:label="us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:to="us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" order="10" use="optional" weight="-1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/BenefitPlansDetailsTextual" xlink:title="06091 - Disclosure - Benefit Plans (Details Textual)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/FairValueMeasurementsDetails" xlink:title="0611 - Disclosure - Fair Value Measurements (Details)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/FairValueMeasurementsDetails1" xlink:title="06111 - Disclosure - Fair Value Measurements (Details 1)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/FairValueMeasurementsDetails2" xlink:title="06112 - Disclosure - Fair Value Measurements (Details 2)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/FairValueMeasurementsDetails3" xlink:title="06113 - Disclosure - Fair Value Measurements (Details 3)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/FairValueMeasurementsDetails4" xlink:title="06114 - Disclosure - Fair Value Measurements (Details Textual)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/BalanceSheetsParenthetical" xlink:title="0111 - Statement - Consolidated Balance Sheets (Parenthetical)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/StatementsOfChangesInShareholdersEquity" xlink:title="0150 - Statement - Consolidated Statements of Changes in Shareholders' Equity (Unaudited)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/Securities" xlink:title="0202 - Disclosure - Securities" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/Loans" xlink:title="0203 - Disclosure - Loans" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/AllowanceForLoanLosses" xlink:title="0204 - Disclosure - Allowance for Loan Losses" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/OtherBorrowings" xlink:title="0206 - Disclosure - Other Borrowings" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/TrustPreferredCapitalNotes" xlink:title="0208 - Disclosure - Trust Preferred Capital Notes" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/BenefitPlans" xlink:title="0209 - Disclosure - Benefit Plans" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/FairValueMeasurements" xlink:title="0211 - Disclosure - Fair Value Measurements" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/CapitalPurchaseProgram" xlink:title="0212 - Disclosure - Capital Purchase Program" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/CapitalPurchaseProgramDetails" xlink:title="0612 - Disclosure - Capital Purchase Program (Details)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/SecuritiesDetail2" xlink:title="06022 - Disclosure - Securities (Details 2)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock" xlink:label="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock" />
    <loc xlink:type="locator" xlink:href="fxnc-20130331.xsd#fxnc_CommunityBankersBankStock" xlink:label="fxnc_CommunityBankersBankStock" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock" xlink:to="fxnc_CommunityBankersBankStock" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_FederalReserveBankStock" xlink:label="us-gaap_FederalReserveBankStock" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock" xlink:to="us-gaap_FederalReserveBankStock" order="10" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_FederalHomeLoanBankStock" xlink:label="us-gaap_FederalHomeLoanBankStock" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock" xlink:to="us-gaap_FederalHomeLoanBankStock" order="5" use="optional" weight="1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/OtherBorrowingsDetailsTextual" xlink:title="0606 - Disclosure - Other Borrowings (Details Textual)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/OtherRealEstateOwned" xlink:title="0205 - Disclosure - Other Real Estate Owned (OREO)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/AccumulatedOtherComprehensiveIncome" xlink:title="0213 - Disclosure - Accumulated Other Comprehensive Income (Loss)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/OtherRealEstateOwnedTables" xlink:title="0505 - Disclosure - Other Real Estate Owned (OREO) (Tables)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/OtherRealEstateOwnedDetails" xlink:title="0605 - Disclosure - Other Real Estate Owned (OREO) (Details)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/OtherRealEstateOwnedDetails1" xlink:title="06051 - Disclosure - Other Real Estate Owned (OREO) (Details 1)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/OtherRealEstateOwnedDetailsTextual" xlink:title="06052 - Disclosure - Other Real Estate Owned (OREO) (Details Textual)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/AccumulatedOtherComprehensiveIncomeTables" xlink:title="0513 - Disclosure - Accumulated Other Comprehensive Income (Loss) (Tables)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/AccumulatedOtherComprehensiveIncomeDetails" xlink:title="0613 - Disclosure - Accumulated Other Comprehensive Income (Loss) (Details)">
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/StatementsOfComprehensiveIncomeLossParenthetical" xlink:title="0131 - Statement - Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) (Unaudited)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/DocumentAndEntityInformation" xlink:title="00 - Document - Document and Entity Information" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/GeneralPolicies" xlink:title="0401 - Disclosure - General (Policies)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/General" xlink:title="0201 - Disclosure - General" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/CapitalRequirements" xlink:title="0207 - Disclosure - Capital Requirements" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/EarningsPerCommonShare" xlink:title="0210 - Disclosure - Earnings per Common Share" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/CapitalRequirementsDetails" xlink:title="0607 - Disclosure - Capital Requirements (Details)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/CapitalRequirementsTables" xlink:title="0507 - Disclosure - Capital Requirements (Tables)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/CapitalRequirementsDetailsTextual" xlink:title="06071 - Disclosure - Capital Requirements (Details Textual)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/EarningsPerCommonShareDetails" xlink:title="0610 - Disclosure - Earnings per Common Share (Details)" />
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/StatementsOfIncome" xlink:title="0120 - Statement - Consolidated Statements of Income (Unaudited)">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact" xlink:label="loc_PreferredStockDividendsIncomeStatementImpact" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="loc_PreferredStockDividendsIncomeStatementImpact" order="20" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="us-gaap_NetIncomeLoss" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="us-gaap_IncomeTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_IncomeTaxExpenseBenefit" order="20" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss" xlink:label="us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestIncomeExpenseNet" xlink:label="us-gaap_InterestIncomeExpenseNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss" xlink:to="us-gaap_InterestIncomeExpenseNet" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestAndDividendIncomeOperating" xlink:label="us-gaap_InterestAndDividendIncomeOperating" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestIncomeExpenseNet" xlink:to="us-gaap_InterestAndDividendIncomeOperating" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestAndFeeIncomeLoansAndLeases" xlink:label="us-gaap_InterestAndFeeIncomeLoansAndLeases" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestAndDividendIncomeOperating" xlink:to="us-gaap_InterestAndFeeIncomeLoansAndLeases" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestIncomeFederalFundsSold" xlink:label="us-gaap_InterestIncomeFederalFundsSold" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestAndDividendIncomeOperating" xlink:to="us-gaap_InterestIncomeFederalFundsSold" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestIncomeDepositsWithFinancialInstitutions" xlink:label="us-gaap_InterestIncomeDepositsWithFinancialInstitutions" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestAndDividendIncomeOperating" xlink:to="us-gaap_InterestIncomeDepositsWithFinancialInstitutions" order="60" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestIncomeSecuritiesTaxable" xlink:label="us-gaap_InterestIncomeSecuritiesTaxable" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestAndDividendIncomeOperating" xlink:to="us-gaap_InterestIncomeSecuritiesTaxable" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestIncomeSecuritiesTaxExempt" xlink:label="us-gaap_InterestIncomeSecuritiesTaxExempt" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestAndDividendIncomeOperating" xlink:to="us-gaap_InterestIncomeSecuritiesTaxExempt" order="100" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DividendIncomeOperating" xlink:label="us-gaap_DividendIncomeOperating" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestAndDividendIncomeOperating" xlink:to="us-gaap_DividendIncomeOperating" order="120" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestExpense" xlink:label="us-gaap_InterestExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestIncomeExpenseNet" xlink:to="us-gaap_InterestExpense" order="40" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestExpenseDeposits" xlink:label="us-gaap_InterestExpenseDeposits" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpenseDeposits" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestExpenseTrustPreferredSecurities" xlink:label="loc_InterestExpenseTrustPreferredSecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestExpense" xlink:to="loc_InterestExpenseTrustPreferredSecurities" order="40" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InterestExpenseBorrowings" xlink:label="us-gaap_InterestExpenseBorrowings" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpenseBorrowings" order="60" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses" xlink:label="us-gaap_ProvisionForLoanLeaseAndOtherLosses" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss" xlink:to="us-gaap_ProvisionForLoanLeaseAndOtherLosses" order="40" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NoninterestIncome" xlink:label="us-gaap_NoninterestIncome" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="us-gaap_NoninterestIncome" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="fxnc-20130331.xsd#fxnc_FeesAndCommissionsFiduciaryAndTrustActivitiesAndAssetManagementFees" xlink:label="fxnc_FeesAndCommissionsFiduciaryAndTrustActivitiesAndAssetManagementFees" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestIncome" xlink:to="fxnc_FeesAndCommissionsFiduciaryAndTrustActivitiesAndAssetManagementFees" order="10" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NoninterestIncomeOtherOperatingIncome" xlink:label="us-gaap_NoninterestIncomeOtherOperatingIncome" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestIncome" xlink:to="us-gaap_NoninterestIncomeOtherOperatingIncome" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestIncome" xlink:to="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" order="30" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_GainLossOnSaleOfSecuritiesNet" xlink:label="us-gaap_GainLossOnSaleOfSecuritiesNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestIncome" xlink:to="us-gaap_GainLossOnSaleOfSecuritiesNet" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_GainLossOnSalesOfLoansNet" xlink:label="us-gaap_GainLossOnSalesOfLoansNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestIncome" xlink:to="us-gaap_GainLossOnSalesOfLoansNet" order="60" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_FeesAndCommissionsOther" xlink:label="us-gaap_FeesAndCommissionsOther" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestIncome" xlink:to="us-gaap_FeesAndCommissionsOther" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="fxnc-20130331.xsd#fxnc_AtmAndCheckCardFees" xlink:label="fxnc_AtmAndCheckCardFees" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestIncome" xlink:to="fxnc_AtmAndCheckCardFees" order="120" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_FeesAndCommissionsDepositorAccounts" xlink:label="us-gaap_FeesAndCommissionsDepositorAccounts" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestIncome" xlink:to="us-gaap_FeesAndCommissionsDepositorAccounts" order="140" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NoninterestExpense" xlink:label="us-gaap_NoninterestExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="us-gaap_NoninterestExpense" order="60" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_GainsLossesOnSalesOfOtherRealEstate" xlink:label="us-gaap_GainsLossesOnSalesOfOtherRealEstate" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_GainsLossesOnSalesOfOtherRealEstate" order="10" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LaborAndRelatedExpense" xlink:label="us-gaap_LaborAndRelatedExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_LaborAndRelatedExpense" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OccupancyNet" xlink:label="us-gaap_OccupancyNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_OccupancyNet" order="60" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_EquipmentExpense" xlink:label="us-gaap_EquipmentExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_EquipmentExpense" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_MarketingExpense" xlink:label="us-gaap_MarketingExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_MarketingExpense" order="100" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SuppliesExpense" xlink:label="us-gaap_SuppliesExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_SuppliesExpense" order="120" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProfessionalFees" xlink:label="us-gaap_ProfessionalFees" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_ProfessionalFees" order="140" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="fxnc-20130331.xsd#fxnc_AtmAndCheckCardFeesExpenses" xlink:label="fxnc_AtmAndCheckCardFeesExpenses" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="fxnc_AtmAndCheckCardFeesExpenses" order="160" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_FederalDepositInsuranceCorporationPremiumExpense" xlink:label="us-gaap_FederalDepositInsuranceCorporationPremiumExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_FederalDepositInsuranceCorporationPremiumExpense" order="180" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="fxnc-20130331.xsd#fxnc_BankFranchiseTax" xlink:label="fxnc_BankFranchiseTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="fxnc_BankFranchiseTax" order="200" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RealEstateOwnedValuationAllowanceProvision" xlink:label="us-gaap_RealEstateOwnedValuationAllowanceProvision" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_RealEstateOwnedValuationAllowanceProvision" order="220" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherNoninterestExpense" xlink:label="us-gaap_OtherNoninterestExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_OtherNoninterestExpense" order="240" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_Communication" xlink:label="us-gaap_Communication" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_Communication" order="260" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ForeclosedRealEstateExpense" xlink:label="us-gaap_ForeclosedRealEstateExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_ForeclosedRealEstateExpense" order="280" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LossOnContractTermination" xlink:label="us-gaap_LossOnContractTermination" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_LossOnContractTermination" order="290" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InformationTechnologyAndDataProcessing" xlink:label="us-gaap_InformationTechnologyAndDataProcessing" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="us-gaap_NoninterestExpense" xlink:to="us-gaap_InformationTechnologyAndDataProcessing" order="300" use="optional" weight="1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://fbvirginia.com/role/StatementsOfIncomeParenthetical" xlink:title="0121 - Statement - Consolidated Statements of Income (Parenthetical) (Unaudited)" />
</linkbase>
