This dataset aims to provide more insight into magnetic core losses at high frequency (MHz range) with superimposed DC bias in ferrites. The tested MnZn ferrite has a nominal relative permeability of 1500 (PC50) and 800 (PC200), which was tested at frequency from 500 kHz to 3 MHz. The DC bias appears to create a shift in the Steinmetz parameters, in particular the ki and β are affected the most. Higher DC bias creates higher losses gain and higher operating frequency makes the relative losses increase lower.