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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-06-12</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001272842</issuerCik>
        <issuerName>AIRGAIN INC</issuerName>
        <issuerTradingSymbol>AIRG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001208317</rptOwnerCik>
            <rptOwnerName>SIMS JAMES K</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O AIRGAIN, INC..</rptOwnerStreet1>
            <rptOwnerStreet2>3611 VALLEY CENTRE DRIVE, SUITE 150</rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92130</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-06-12</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>324035</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1082006</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>220594</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents a distribution in-kind to certain shareholders of Gen 3 Partners, Inc. (&quot;Gen 3 Partners&quot;) for no value.</footnote>
        <footnote id="F2">Represents 1,043,464 shares of common stock held by GEN3 Capital I, LP (&quot;GEN3 Capital&quot;) and 38,542 shares of common stock held by Gen 3 Partners.</footnote>
        <footnote id="F3">The general partner of GEN3 Capital is GEN3 Capital Partners, LLC (&quot;GEN3 LLC&quot;), and James K. Sims is the Managing Member of GEN3 LLC. As a result, each of GEN3 LLC and Mr. Sims may be deemed to share beneficial ownership of the shares held by GEN3 Capital. Mr. Sims, Francis X. Egan, Arthur M. Toscanini and Michael Treacy may be deemed to share beneficial ownership of the shares held by Gen 3 Partners in their capacity as directors of Gen 3 Partners. Each of the individuals and entities listed herein disclaims such beneficial ownership except to the extent of his or its pecuniary interest therein.</footnote>
        <footnote id="F4">Includes 80,447 shares acquired on June 12, 2017 in a distribution in-kind to certain shareholders of Gen 3 Partners for no value, which acquisition was exempt under Rule 16a-13.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ James K. Sims</signatureName>
        <signatureDate>2017-06-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
