A method for modifying reaction rate parameters in the Arrhenius rate equation for combustion of methane is proposed. Linear least-squares data fit to measured concentrations and temperatures is used to modify reaction rate parameters in the Arrhenius rate equation for combustion of methane in one step. The modified equation is compared to the one provided by the software Fluent by implementing both into a three-dimensional Fluent simulation. The modification of reaction rate parameters influences the result of computational fluid dynamics simulations to predict combustion at experimental conditions where the Fluent rate equation failed. With modified parameters, the size of the reaction zone increases to give better agreement with experiments than that obtained using the Fluent rate equation. This first test indicates that the method has the contingency of becoming a useful tool for modification of reaction rate parameters though it still needs further development.