The ratio between magnetic and nuclear small angle neutron scattering (SANS) can provide additional information about the composition and structure of the scattering inhomogeneities. The method fails if the material system does not meet the two-phase approach. In this case, the ratio can more generally be defined and related to the dependence of the scattering particle size by using the indirect transformation method. The method is derived and applied to model systems with two types of non-magnetic spheric inhomogeneities in a ferromagnetic matrix. (C) 2000 Elsevier Science B.V. All rights reserved.