What this converter does
This converter turns a frequency into its wavelength and back. The two are inversely related through the wave’s speed: a higher frequency means a shorter wave. Enter the propagation speed — the speed of light by default — and read the wavelength instantly.
Use 3×10⁸ m/s for radio and light in vacuum or air. For a transmission line, enter the medium’s velocity of propagation to get the true physical length.
The units it covers
Wavelength and frequency are inversely linked through the wave’s speed in its medium — light in vacuum, or slower in cable or fibre.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Wavelength | m | λ | Physical length of one cycle |
| Frequency | Hz | f | Cycles per second |
| Velocity | m/s | v | Wave speed (c = 3×10⁸ in vacuum) |
The formula
Wavelength equals the propagation speed divided by frequency, so the two are inversely proportional at a given velocity:
λ = v ÷ fWhere:
- λ = wavelength in metres
- f = frequency in hertz
- v = propagation velocity (m/s)
Worked example
Find the wavelength of a 2.4 GHz Wi-Fi signal in air.
λ = v ÷ f299792458 ÷ 2.4×10⁹ ≈ 0.125 mSo 2.4 GHz has a wavelength of about 12.5 cm in air.
The units in this example
Cycles per second. A higher frequency gives a shorter wavelength at the same speed.
- 2.4 GHz ≈ 0.125 m
- 300 MHz ≈ 1 m
- 1 GHz ≈ 0.30 m
- f = v ÷ λ
The physical length of one cycle. Longer for lower frequencies at a fixed speed.
- 0.125 m ≈ 2.4 GHz
- 1 m ≈ 300 MHz
- 0.30 m ≈ 1 GHz
- λ = v ÷ f