A simple model of heat transfer within a dynamic calorimeter is introduced. On the basis of this model the measured signal of a known thermal event in the sample can be calculated. For this result a method is developed to estimate the true transition temperature and enthalpy from only one heating run. The method is valid on melting peaks with and without a stepwise change of heat capacity. The new method has been experimentally verified for different pure substances. This method can be used as a simple and fast calibration check for a differential scanning calorimeter.