Wavelength Calculator
Find the wavelength of a wave from its speed and frequency.
m/s
Hz
- 1
Wave speed
v = 299,792,458 m/s = 299,792,458 - 2
Frequency
f = 100,000,000 Hz = 100,000,000 - 3
Wavelength λ = v ÷ f
299,792,458 ÷ 100,000,000 = 2.997925
Formula
How this is calculated
This calculator applies the wave equation λ = v / f, where v is the wave speed in metres per second and f is the frequency in hertz (cycles per second). It simply divides the speed you enter by the frequency, so a wave that travels v metres each second and repeats f times per second covers v / f metres per cycle — that distance is the wavelength λ, expressed in metres.
The wave speed defaults to the speed of light in a vacuum, c ≈ 299,792,458 m/s, which is correct for light and radio waves travelling through empty space. For sound or for waves in any other medium you should replace it with the appropriate propagation speed (about 343 m/s for sound in air at room temperature). The frequency must be greater than zero, since dividing by zero has no physical wavelength.
The result is shown in metres and also converted to centimetres (×100) and nanometres (×1,000,000,000) for convenience. The model assumes a single constant speed and a steady frequency in a non-dispersive medium; it does not account for refractive index changes, dispersion, or Doppler shifts.
Examples
| Input | Result |
|---|---|
| v = 299,792,458 m/s, f = 100 MHz | λ ≈ 2.998 m |
About this calculator
A wave’s wavelength (λ) is the distance between successive crests. It equals the wave speed divided by the frequency: λ = v / f. With speed in metres per second and frequency in hertz, the wavelength comes out in metres.
For electromagnetic waves such as light and radio in a vacuum, the speed is the speed of light, c ≈ 299,792,458 m/s, which is the default here. For sound, use the speed of sound in the medium instead (about 343 m/s in air at room temperature). Higher-frequency waves have shorter wavelengths, and vice versa.
Frequently asked questions
Wavelength equals wave speed divided by frequency: λ = v / f. Use m/s and hertz to get the wavelength in metres.
For light or radio waves in a vacuum, use the speed of light (≈ 299,792,458 m/s). For sound, use the speed of sound in your medium, such as ~343 m/s in air.
They are inversely proportional for a fixed wave speed: as frequency increases, wavelength decreases, and their product always equals the wave speed.
Also known as
TG we-Calculate Editorial Team. (2026). Wavelength Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/wavelength-calculator
TG we-Calculate Editorial Team. "Wavelength Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/wavelength-calculator.
TG we-Calculate Editorial Team, "Wavelength Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/wavelength-calculator
@misc{wecalculate_wavelength_calculator, title = {Wavelength Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/wavelength-calculator}}, year = {2026}, note = {TG we-Calculate} }
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