This paper presents different methods to determine the parameters for the equivalent electrical circuit model of a high-frequency planar transformer. The first method is implemented in the circuit simulation software utilizing a 1-D electromagnetic analysis. The second method uses a 3-D electromagnetic analysis and is implemented in a finite-element analysis software. The third method is a differential evolution (DE)-based algorithm using the experimental transformer data. The first two methods are useful in the design stage to predict the performance of a planar transformer, while the third one can be applied to validate the design. The performance and accuracy of the three methods are assessed by comparing each method’s parameter estimate of an actual planar transformer. The comparison showed that the predictions of magnetizing inductance by the two numerical analyses are accurate and comparable with that of the DE-based estimation method. However, the series resistance and leakage inductance determined by the DE algorithm tend to be higher, as predicted by the two numerical methods, due to the nonconsideration of the measuring leads impedance in the numerical models.