The iron losses are calculated from the sum of the eddy current losses and hysteresis losses. They are difficult to calculate exactly in advance, as the local flow conditions and the processing of the sheets influence the values. Since the iron losses are dependent on the change in magnetic flux density, specific values per kg of iron are given for a selected flux density, flux direction and frequency. Depending on the iron quality and sheet thickness, the iron losses are between 0.8 and 12 W/kg at a flux density of 1.5 T and a frequency of 50 Hz.