SUMMARYThe normal procedure in calculating the effective induced magnetisation of bodies is to introduce the demagnetisation factor. The theory of calculating the demagnetisation factor is however restricted to bodies of 2nd degree surface lying in a homogeneous field i.e. homogeneously magnetised bodies. All other bodies have to be approximated.Here, the method is based on iterative calculation of magnetisation fields, which makes it possible to calculate the effective magnetisation of any bodies, when the distribution of the inducing field and susceptibility are known.