Based on the Gibbs-Tolman-Koenig formalism, we considered the Tolman correction to the free energy barrier of bubble nucleation in polymer-gas binary mixtures. For this class of systems, the correction may be estimated with a reasonable accuracy using experimentally accessible macroscopic thermodynamic quantities only. Although the Tolman correction is applicable only in the low supersaturation regime, a simple ansatz regarding the supersaturation dependence of the Tolman length can be made to extend the usefulness of this approach and to yield the free energy barrier that vanishes at the mean-field spinodal as demanded by thermodynamic considerations. (c) 2013 American Institute of Chemical Engineers AIChE J, 59: 3042-3053, 2013