The computation of the reverse rate of an elementary reaction given the forward rate and requisite thermodynamic data is well established. Nevertheless the procedure is extremely laborious and error prone, in particular, when large numbers of such calculations must be performed and the results fitted to traditional or extended forms of the Arrhenius rate constant equation. We have developed a software application, CHEMRev, which automatically performs such computations for Chemkin-style reaction mechanisms. (C) 2005 Wiley Periodicals, Inc. Int.