This article presents a verification of a simple numerical model that uses the cell resistance as the only experimental parameter. Two methods for determining this experimental parameter are evaluated by comparing the actual measured cell voltages with the calculated cell voltages at various gas utilizations and current loads. Furthermore, the results of the model are compared with the analytical fuel cell model that was previously developed at Delft University. Both the simple numerical model and the analytical fuel cell model use isothermal electrochemical relations for determination of the performances. In order to assess this numerical model for application to non-isothermal molten carbonate fuel cell stacks found in practice, the discrepancy between the results from the isothermal model and the non-isothermal model is discussed. The maximum relative discrepancy between the measured and calculated cell voltage by the numerical model was 3%. This discrepancy was reduced to 1.7% when using a fitted value for the cell resistance. Comparison of the results of the isothermal and non-isothermal models shows that the differences in results can, in general, be neglected.