The explicit finite difference formulation of an inverse heat transfer model to calculate the heat flux generated by induction is developed. The experimentally measured temperature data are used as the input for the inverse heat transfer model. This model is particularly suitable for a workpiece with low cross section Biot number. Induction heating experiments are carried out using a carbon steel rod. The finite difference method and thermocouple temperature measurements are applied to estimate the induction heat flux and workpiece temperature. Compared to measured temperatures, the accuracy and limitation of proposed method is demonstrated. The effect of nonuniform temperature distribution, particularly in the heating region during the induction heating, is studied. Analysis results validate the assumption to use the uniform temperature in a cross section for the inverse heat transfer solution of induction heat flux. Sensitivity to the grid spacing, thermocouple location, and thermophysical properties are also studied.