Numerical dosimetry makes it possible to evaluate the influence of electromagnetic fields on the human body. The interest of performing numerical dosimetry starting from data coming from general purpose software or measurements is constantly growing. This paper compares two available methods that make dosimetry starting from the knowledge of the magnetic flux density. The quality of results is analyzed considering both exact and uncertain inputs stressing out when one method should be preferred over the other. Finally, the methods are validated using real measurements obtaining good results.