The identification of different loss mechanisms and the prediction of exact power dissipations play a significant role in the development of new electric motor designs and the achievement of highest power densities and, therefore, high continuous drive powers. As many approaches exist to estimate the ohmic losses in the windings of a motor and additional mechanical losses, such as bearing losses, the most significant calculation error is usually made in the iron loss estimation of the stator core. In this paper, an analytic calculation method of the iron losses is presented, which gives the opportunity to predict the stator's losses without time-consuming 3D FEM calculations. The basis of the calculation model are commonly known material parameters of the lamination sheet and the insulation varnish, as well as geometric parameters of the target geometry. The result of the loss model is compared and validated with measurement values, delivered by a novel test device for stator segments.