Wavelength Calculator
Free wavelength calculator using v = f·λ — solve for wavelength, frequency, or wave speed, with sound and light presets and an animated wave.
Everyday Uses
Physics homework
Use v = f·λ to solve for wavelength, frequency, or wave speed.
Radio & Wi-Fi
Find the wavelength of a radio station or Wi-Fi channel from its frequency.
Music & sound
Work out the wavelength of a musical note travelling through air or water.
Light & colour
Relate the frequency of light to its wavelength across the spectrum.
Frequently Asked Questions
What is the formula for wavelength?
Wavelength is λ = v ÷ f, where v is the wave speed and f is the frequency in hertz (Hz). A 686 Hz sound in air (speed 343 m/s) has wavelength λ = 343 ÷ 686 = 0.5 m. The same wave equation rearranges to f = v ÷ λ and v = f × λ.
How are wavelength and frequency related?
For a fixed wave speed, wavelength and frequency are inversely proportional: as frequency goes up, wavelength gets shorter. Doubling the frequency halves the wavelength. This is why high-pitched sounds and high-frequency radio waves have shorter wavelengths than low-pitched or low-frequency ones.
What wave speed should I use?
Use the speed of the medium: sound in air is about 343 m/s (at 20 °C), sound in water about 1,480 m/s, and light or radio waves travel at c ≈ 299,792,458 m/s in a vacuum. This calculator includes presets for each so you only need the frequency or wavelength.