Science & Engineering

Wave Speed Calculator (v = f x lambda)

A wave's speed equals its frequency times its wavelength. Enter any two of speed, frequency, and wavelength to solve for the third, with results in six unit conventions.

How to use
  1. Enter any two of frequency, wavelength, and speed.
  2. Switch the output between the available speed units.
Wave
Wave propagation speed

v = f × λ

In km/h
In mph
Fraction of c
Mach (air 20°C)
For study and estimation. Verify against authoritative data before relying on a result.
Was this helpful?

How it's calculated

v = f × λ

v = wave speed (m/s), f = frequency (Hz), λ = wavelength (m). The fundamental wave relation.

Worked examples

FrequencyWavelengthSpeedNote
256 Hz1.34 m343 m/sSound in air
100 MHz3 m3.0 x 10^8 m/sFM radio in vacuum
2 Hz0.5 m1 m/sWater ripple

Common questions

What is the wave speed equation?

v = f x lambda, where v is speed, f is frequency, and lambda is wavelength. Higher frequency with the same wavelength means a faster wave.

Does frequency or wavelength change the speed?

In a given medium the speed is fixed, so raising the frequency shortens the wavelength and vice versa. Speed itself changes only when the medium changes.