The low component count, high full-load efficiency, and simplicity of hard-switched dc-dc converters in the low-to-medium frequency range lead to a low-cost and low weight/volume solution for high-power dc-dc converters. The choice of the magnetic material is critical in order to optimise the size of the inductor. In this paper, a novel inductor-design algorithm is developed and automated in order to contrast and compare various magnetic materials, such as iron-based amorphous metal, 6.5% silicon steel, nanocrystalline, and ferrite, for use in a gapped CC-core inductor. The algorithm considers skin and layer effects for the foil, core losses, and gap losses for the laminated materials.