This paper deals with Axial Flux Permanent magnets Machine (AFPM) for hybrid electric vehicles and the sizing of one of those. The two first parts (Sections 1 and 2) draw the academic and industrial context up with a short and summed up state of the art. The third section (Section 3) is dedicated to a geometrical modelling compatible with axial structures and conception needs. In the fourth and fifth sections (Sections 4 and 5), the magnetic and thermal modellings of one prototype are built and simulated thanks to three different methods. Before the end (Section 6), calculations are compared to each other, to an accurate finite element analysis and finally to experimental results. The aim is to propose an optimal design with the help of gradual sizing methods. Outlooks are discussed in the conclusion (Section 7).