Wavelength Calculator
Calculate the wavelength of any wave from its speed and frequency using λ = v ÷ f.
How it works
- 1Enter the wave speed (m/s). Sound in air travels at ≈ 343 m/s; light in a vacuum at 3×10⁸ m/s.
- 2Enter the frequency in hertz (Hz). For example, a concert A note is 440 Hz.
- 3The calculator divides speed by frequency (λ = v ÷ f) and shows the wavelength in metres, centimetres, and nanometres.
Use cases
- Audio engineering — the wavelength of a speaker’s fundamental frequency for room acoustics.
- Optics and photonics — converting visible-light frequencies to nanometre wavelengths.
- Radio and RF design — antenna element lengths are fractions of the signal wavelength.
Frequently asked questions
What is the formula for wavelength?
Wavelength λ (metres) = wave speed v (m/s) ÷ frequency f (Hz). For example, sound at 343 m/s and 440 Hz gives λ = 343 ÷ 440 ≈ 0.78 m.
What wave speed should I use for sound versus light?
Use 343 m/s for sound in air at 20 °C. For light in a vacuum use 3×10⁸ m/s. Light slows inside glass or water, so use the medium’s actual speed when precision matters.
Why does the result show — instead of a number?
A frequency of 0 Hz would require dividing by zero, which is undefined. Enter any positive frequency and the wavelength appears immediately.
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