Duty Cycle Calculator

Find the duty cycle percentage and frequency of a pulsed signal from its pulse width and period.

Pulse Width (ON time)

Period (total cycle time)

What Duty Cycle Means

Duty cycle describes the fraction of time a repeating signal spends ‘on’ compared to its full cycle. It’s a key concept for PWM motor control, LED dimming, switching power supplies, and any pulsed electronic signal.

The Formula

Duty Cycle (%) = (Pulse Width ÷ Period) × 100, and Frequency (Hz) = 1000 ÷ Period (ms). A 50% duty cycle means the signal spends equal time on and off each cycle; a lower percentage means shorter, less frequent pulses.

Make sure pulse width and period are measured in the same time units before comparing results. This tool is for general electronics reference and educational use.

Last reviewed August 2026