The Dowell expression is the most commonly used method for the analytic calculation of the equivalent resistance in windings of magnetic components. Although this method represents a fast and useful tool to calculate the equivalent resistance of windings, it cannot be applied to components that do not fit with classical 1D assumption, which is the case of gapped magnetic components. These structures can be accurately analyzed using finite-element analysis (FEA) with the time cost that this represents. Modifying the Dowelĺs equation, and taking advantage of the orthogonality between skin and proximity effects, a simple solution that allows its application in gapped magnetic components is proposed in this work, which results shows a very good accuracy compared with experimental measurements.