The method of evaluating the magnetocaloric effect (MCE) and heat capacity of various magnetic samples from calorimetric experiments are presented. This method allows determining the MCE of the magnetic solid samples of indefinite shape, the MCE of microparticles in suspensions and the MCE of magnetic nanoparticles in the colloids. The method was tested on a gadolinium metal, which has one of the biggest values of MCE at room temperature. The observed data, compared with other experimental works, are in a good agreement, and it confirms the practicality of this method.