The formulas of output and ripple voltage from voltage multiplying rectifier are found in reference. The formulas are deduced on the condition of continuous simple harmonic waves. The corresponding formulas for input of pulse width modulating rectangle waves have not been found yet. In this study, pulse width modulating rectangle waves of high frequency are adopted as input of a voltage multiplying rectifier circuit, for validating the formulas. The effects of duty cycle parameter on the formulas were experimentally measured. Then new empirical formulas including duty cycle parameter are found. The applicability of new empirical formulas is also tested.