The main purpose of this paper is to incorporate a reÿned hysteresis model, viz., a vector Preisach model, in 2-D magnetic ÿeld computations. Two complementary formulations, based either on the scalar or on the vector potential, are considered. The governing Maxwell equations are rewritten in a suitable way, that allows to take into account the proper magnetic material parameters and, moreover, to pass to a variational formulation. The variational problems are solved numerically by a Finite Element approximation, using a quadratic mesh, followed by a time discretization method based upon a modiÿed Cranck-Nicholson algorithm. Finally, the e ectiveness of the presented mathematical tools have been conÿrmed by several numerical experiments, comparing the complementarity of the two procedures. ? 1998 John Wiley & Sons, Ltd.