About The PWM Duty and Frequency Calculator

The PWM Duty and Frequency Calculator converts between period/on-time and frequency/duty cycle for pulse-width modulated signals.

How to Use the PWM Calculator Online

1. Choose whether you know period plus on-time or frequency plus duty cycle.
2. Enter the matching timing values.
3. Run the calculator to see the equivalent PWM representation.

Choosing Options Correctly

Keep units consistent and confirm controller timer resolution, prescalers, minimum pulse width, switching losses, and load behavior. Hardware PWM outputs may quantize timing differently than the ideal values.

Common Use Cases

• Set LED dimming or motor-control PWM values.
• Convert a measured waveform into frequency and duty cycle.
• Check firmware timer settings against desired timing.

Quick FAQ

Can on-time exceed period?
No. On-time must be less than or equal to the period; otherwise the duty cycle would be above 100 percent.

Does this account for timer register limits?
No. Microcontroller prescalers, counter width, clock accuracy, and resolution must be checked separately.

What is the tradeoff between frequency and resolution?
Higher PWM frequency usually leaves fewer timer counts per period, reducing duty-cycle resolution.

Can I use it for motor or LED control?
Use it for timing math, then verify switching losses, audible noise, driver limits, filtering, and load response.