A numerical implementation of the classical Stoner–Wohlfarth (SW) model to simulate the magnetization angle of an assembly of SW particles with an effective axis of anisotropy under a rotating applied field is presented. Using an angular distribution for the angle each SW particle is making with the medium’s reference axis, the proposed model successfully simulated lag-angle plots exhibiting the same rotational magnetization behavior measured for different ellipsoidally magnetizable media in the literature. The developed algorithm provides a simple tool for rotational-energy-loss calculations, preserves the physical intuition of the classical SW model, and is computationally faster compared to the Preisach–Stoner–Wohlfarth models. The effect of the angular distribution parameters on the switching transition angle and the algorithm’s potential for modeling additional anisotropies through using different angular distributions are discussed.