This paper presents a simplification method for finite element models for the calculation of ac losses in stacks of superconducting tapes. A fast and accurate model of these losses can be exploited in the design of large-scale superconducting applications, where the coils are represented as stacks of tapes in 2-D models. The simplification method aggregates the superconducting, substrate, and copper layers of several windings of the superconducting tape to form bulk elements. The resulting model is able to evaluate the ac losses in the superconducting layer faster than the full model. The accuracy of the proposed method and decrease in computation time are shown.