What is the formula for Waveform Form Factor?

The Waveform Form Factor formula is FF = Vrms / Vavg, where FF—Form factor (dimensionless); Vrms—RMS value of the waveform (V); Vavg—Average (rectified mean) value (V).

What does FF mean in the Waveform Form Factor formula?

FF is Form factor (dimensionless).

Waveform Form Factor

Q: How do you calculate Waveform Form Factor?

Use the formula FF = Vrms / Vavg. The form factor of a waveform is the ratio of its RMS value to its average (rectified mean) value, and it characterises the shape independent of amplitude. Enter the values you know in the calculator above and it solves for the remaining variable.

FF = Vrms / Vavg

Calculator

Form Factor

RMS Value

Average Value

Result

—

Formula

FF = Vrms / Vavg

Description

The form factor of a waveform is the ratio of its RMS value to its average (rectified mean) value, and it characterises the shape independent of amplitude. A pure sine wave has a form factor of about 1.11; a square wave is 1.0; sharper, peakier waveforms have larger form factors. It is used to relate average-reading meters to true RMS and to characterise rectified outputs.

Variables

FF — Form factor (dimensionless)
Vrms — RMS value of the waveform (V)
Vavg — Average (rectified mean) value (V)

Practical Notes

Average-responding AC meters are calibrated assuming a sine (×1.11); they misread non-sinusoidal signals. Together with the crest factor (peak/RMS) the form factor describes a waveform’s shape.

Related Concepts

All AC Circuits formulas →

Resonant Frequency Impedance (RLC Series) Quality Factor (Bandwidth) Quality Factor (RLC) Power Factor Apparent Power Reactive Power RLC Circuit Bandwidth

Need more features?

Save calculations, import telemetry data, simulate battery discharge, and collaborate with your team.

Try the App