<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2014-06-04</periodOfReport>

    <dateOfOriginalSubmission>2014-06-06</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000887936</issuerCik>
        <issuerName>FTI CONSULTING INC</issuerName>
        <issuerTradingSymbol>FCN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001550674</rptOwnerCik>
            <rptOwnerName>Costamagna Claudio</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>555 12TH STREET NW</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 700</rptOwnerStreet2>
            <rptOwnerCity>WASHINGTON</rptOwnerCity>
            <rptOwnerState>DC</rptOwnerState>
            <rptOwnerZipCode>20004</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-06-05</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1213</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.98</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12586</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares were withheld for taxes for the issuance of shares of common stock upon the vesting of restricted stock units on June 5, 2014 and were inadvertently omitted from the Form 4 filed on June 6, 2014. These shares were also inadvertently omitted from subsequent Forms 4 filed by the reporting person on June 5, 2015, June 3, 2016, and June 7, 2016.</footnote>
        <footnote id="F2">The 12,586 of securities beneficially owned by the reporting person are comprised of the 8,403 restricted stock units granted on June 6, 2012 that vested and converted to common shares on June 6, 2013, minus the 1,344 shares withheld for taxes upon the vesting of restricted stock units, which were reported on the Form 4 filed on July 12, 2013. The securities are also comprised of the 6,740 restricted stock units granted on June 5, 2013 that vested and converted to common shares on June 5, 2014, which were reported on the Form 4 filed on June 6, 2014, minus the 1,213 shares withheld for taxes upon the vesting of restricted stock units reported on this amended Form 4 filed on July 5, 2017.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>By: Joanne Catanese, Attorney-in-Fact For: Claudio Costamagna</signatureName>
        <signatureDate>2017-07-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
