PWM Duty Cycle Calculator

How PWM dimmers and motor controllers work.

PWM switches full voltage on and off quickly. The average sets brightness or speed. Everything is worked out in your browser. Nothing is saved or sent anywhere.

1. The signal

2. Supply

3. Results

How it was worked out

    What this does and doesn't tell you

    • A normal meter on DC volts shows roughly the average. A meter with a duty-cycle setting reads it directly.
    • 240V AC mains can kill. In Australia, work on household mains wiring must be carried out by a licensed electrician. Low-voltage DC systems can still deliver very high current.
    ↑