Wave Speed Calculator
Calculate wave speed from frequency and wavelength using v = f·λ in metres per second.
How it works
- 1Enter the wave’s frequency in hertz (Hz) — for example, 440 Hz for concert-A pitch.
- 2Enter the wavelength in metres (m) — the distance between successive crests or compressions.
- 3The calculator applies v = f·λ and displays wave speed in m/s along with the equivalent in km/h.
Use cases
- Verify that a 440 Hz sound wave in air has a wavelength of ≈ 0.78 m at the speed of sound (343 m/s).
- Convert radio or microwave frequencies to wave speed when the wavelength is known.
- Check ocean or seismic wave propagation speed from measured frequency and wavelength.
Frequently asked questions
What is the wave speed formula?
Wave speed v equals frequency f times wavelength λ: v = f·λ. Frequency is in hertz (Hz) and wavelength in metres (m), giving m/s. It holds for all periodic waves — sound, light, water, seismic, and electromagnetic.
How does the wave-speed relationship work?
A wave moves one full wavelength forward per cycle. If it completes f cycles per second and each spans λ metres, the wavefront travels f × λ metres per second. In a given medium, doubling the frequency halves the wavelength, so the speed stays constant.
Can I use this for sound, light, and radio waves?
Yes. A 440 Hz note in air has λ ≈ 0.78 m, giving v ≈ 343 m/s — the speed of sound. For light, 550 nm at 5.45×10¹⁴ Hz gives v ≈ 3×10⁸ m/s. Enter any frequency and wavelength.
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