Copper losses in magnetic coils depend on several geometrical parameters, as well as on frequency, in a way that makes their modeling a quite difficult task. In this paper a finite element analysis (FEA) software is utilized for the investigation of a series of issues critical for the accurate determination of copper losses in layered coils with round wires or foils. Some of the issues investigated are the edge effect in foil and round wire windings as well as the effect of the winding pitch on the copper losses. The results that come up from this work help to fully understand the real impact of two dimensional (2D) effects in layered windings of real rather than ideal magnetic components and they consist a tool for the accurate calculation of the encountered losses, which is necessary for an optimized magnetic component design.