The nonlinear isoconversional method has been applied to data for non-isothermal thermal decomposition of calcium carbonate. The activation energy determined by this method is dependent on the extent of reaction. The dependence of the activation energy has been used to predict the isothermal kinetics. It is shown that the dependence derived from non-isothermal data permits reliable predictions of the isothermal kinetics. Therefore, the nonlinear isoconversional method is recommended as a trustworthy way of obtaining consistent kinetic information from isothermal and non-isothermal. (C) 2014 Elsevier B.V. All rights reserved.