In cases where the current through the junction of a Schottky diode can be described by thermionic emission (TE) theory, a method is presented to calculate the device parameters using forward bias I–V data. In the presented method, (V–IR S)/nβ = Λ(V) was defined as a variable. The values of the new variable Λ(V) were determined by using the characteristic variation of the power exponent α(V) with bias voltage. Device parameters such as the zero-bias barrier height ∅ BO , ideality factor n and series resistance R S were calculated analytically using power exponent α(V) together with Λ(V) without any limitation. The performance of the method in calculating parameters was tested using simulated and real (I–V) data. Simulated (I–V) data was formed systematically with different values of n, R S and ∅ BO for five temperatures. The parameter values calculated from these (I–V) data using the suggested method were compared with the values used to create the simulated (I–V) data. Second, the method was tested using I–V data of real Schottky structures. Experimental (I–V) data of the Re/n-GaAs and Au/(SnS-doped PVC)/n–Si Schottky diodes measured at various temperatures were used. The currents were recalculated using the parameters calculated from both simulated (I–V) and real (I–V) data. These currents were compared with the initial currents for each temperature.