Pulse width is the length of activation within a signal. This specification is used to determine the overall signal generated by a specific voltage over its duty cycle. This calculation is used extensively in the fields of electronics, engineering and signal analysis. At its core, the determination of pulse width is a calculation of a ratio. This ratio is the amount of time, per cycle, that a signal is actively drawing voltage.

Create a ratio that places the length of the cycle activity in the numerator and the length of the overall cycle in the denominator.

Divide the numbers.

Multiply the result by 100 percent. This yields the pulse width of the duty cycle. This percentage may be used later to determine the overall voltage of the signal given an input voltage value.