POWER OF ATTORNEY

KNOW ALL BY THESE PRESENTS, that the undersigned hereby authorizes Stephen A.
Remondi and Richard F. Gilbody of Exa Corporation, a Delaware corporation (the
"Company"), and John D. Patterson, Jr., Robert W. Sweet, Jr. and Daniel S.
Clevenger of Foley Hoag LLP, each acting singly, to execute for and on behalf of
the undersigned, in the undersigned's capacity as a director or executive
officer of the Company, Forms 3, 4 and 5, and any amendments thereto, and cause
such form(s) to be filed with the United States Securities and Exchange
Commission pursuant to Section 16(a) of the Securities Exchange Act of 1934,
relating to the undersigned's beneficial ownership of securities in the Company.
The undersigned hereby grants to the attorney-in-fact full power and authority
to do and perform any and every act and thing whatsoever requisite, necessary or
proper to be done in the exercise of any of the rights and powers herein
granted, as fully to all intents and purposes as the undersigned might or could
do personally present, with full power of substitution, resubstitution or
revocation, hereby ratifying and confirming all that such attorney-in-fact, or
such attorney's-in-fact substitute or substitutes, shall lawfully do or cause to
be done by virtue of this power of attorney and the rights and powers herein
granted. The undersigned acknowledges that the foregoing attorney-in-fact, in
serving in such capacity at the request of the undersigned, is not assuming, nor
is the Company assuming, any of the undersigned's responsibilities to comply
with Section 16 of the Securities Exchange Act of 1934.

This Power of Attorney revokes the authority of any person named in any prior
power of attorney relating to the undersigned's filing obligations pursuant to
Section 16(a) of the Securities Exchange Act of 1934, relating to the
undersigned's beneficial ownership of securities in the Company.  This Power of
Attorney shall remain in full force and effect until the undersigned is no
longer required to file Forms 3, 4 and 5 with respect to the undersigned's
holdings of, and transactions in, securities issued by the Company, unless
earlier revoked by the undersigned in a signed writing delivered to the
foregoing attorney-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 25th day of January, 2016.


                                            /s/ Jean-Paul Roux
                                            --------------------------------
                                            Jean-Paul Roux