Designing inductors in Power Electronics PWM inverter requires accounting for losses generated in these components, including saturation. This paper investigates the design of the AC output inductors of a PWM inverter. The induction waveform of the output inductor is first computed, taking into account a variable saturation state of the core. This enables to compute the core losses using iGSE in a particular analytical formulation. Furthermore a high frequency copper losses model applied to Litz wire is presented and validated using impedance measurement. A calorimetric method is used to measure and determine the area of validity of these core and copper losses models. With a calibration step, the global measurement error is below 0.2W. Over dozens of experiments carried out in different conditions, results show the importance of the choice of Steinmetz coefficients if the signal has multiple frequencies. The effect of the saturation on the waveform and on the losses is also depicted.