Ring core inductors are widely used as filter components for electromagnetic interferences mitigation. In order to design these filters with accuracy, a behavioral model of the inductors, based on an equivalent electrical circuit, is proposed in this paper. This model takes into account the frequency-dependent impedance of ferrite and nanocrystalline ring core inductors. The main contribution of this model is the inclusion of the capacitive effects (dielectric behavior) of the ferrite material, the skin effect in the nanocrystalline material and the parameterization of the electrical equivalent model as a function of number of winding turns. The proposed Behavioral Ring Core Inductor (BRCI) model is used in the simulations and the obtained results are validated by the measurements.