Convert between wave frequency, period and wavelength for a given wave speed, with angular frequency included.
Default speed 343 m/s is sound in air at 20 °C. Use 3 × 10⁸ m/s for light in vacuum, or 1,480 m/s for sound in water.
Frequency
How to use this tool
Choose frequency in hertz or period in seconds as your starting value.
Type the wave speed in m/s — 343 for sound in air, about 3 × 10⁸ for light in vacuum.
Frequency, period and wavelength are shown together, so any one of them gives you the other two.
The same relations describe sound waves, radio waves and AC mains: 50 Hz mains has a 0.02 s period.
Formula & worked example
A 50 Hz sound wave in air (343 m/s) has period 1 / 50 = 0.02 s and wavelength 343 / 50 = 6.86 m.
Limitations — read this before you rely on it
This assumes a simple periodic wave with a single, constant wave speed. In dispersive media the speed varies with frequency, and real signals contain a spread of frequencies.
Frequently asked questions
Frequency counts cycles per second (Hz); period is the time for one cycle (seconds). They are reciprocals.
Wavelength = wave speed / frequency. Faster waves or lower frequencies give longer wavelengths.
Frequency in radians per second: ω = 2πf. A 50 Hz wave has ω ≈ 314 rad/s.
About 6.86 m in air at 343 m/s.
No — frequency stays the same; speed and wavelength change instead.