A simple approach was developed for numerical evaluation of unknown parameters of Williams-Landel-Ferry equation used for non-linear analysis. The approach consists of an iterative process, where each iteration is reduced to a linear regression problem with respect to a specific set of parameters. The process continues until the required accuracy is satisfied. The approach accounts for the non-linearity of deformation, shows fast convergence, and offers high statistical reliability. Good correlation was found between predicted and measured magnitudes of storage modulus for an elastomer considered in this study.