Wavelength Calculator
Wavelength from frequency (or the reverse) for sound, light or any wave speed.
Quick answer
- Formula: λ = v ÷ f; f = v ÷ λ
- Worked example — Wavelength: 0.779545 m (full example below).
Wavelength Calculator
| Wavelength | 0.779545 m |
| Frequency | 440.0000 Hz |
| Wave speed used | 343.00 m/s |
Concert A (440 Hz) has a wavelength of about 0.780 m in air at 20 °C.
Every wave obeys v = f × λ: wave speed equals frequency times wavelength. Give any two of the three quantities and the third follows.
Presets cover sound in dry air at 20 °C (343 m/s) and light in vacuum (c = 299,792,458 m/s exactly), or enter a custom speed — for example about 1,480 m/s for sound in water.
The formula
Worked example
Concert A (440 Hz) has a wavelength of about 0.780 m in air at 20 °C.
The example is pre-loaded in the result panel — press Calculate with your own numbers to replace it.
Frequently asked questions
What is the wavelength of FM radio?
FM broadcasts around 100 MHz. With light mode selected, 100,000,000 Hz gives λ ≈ 3.0 m — which is why FM antennas are roughly that scale.
Does the speed of sound change with temperature?
Yes — about 331 m/s at 0 °C, rising roughly 0.6 m/s per degree. This calculator's preset uses the standard 343 m/s at 20 °C; use a custom speed for other temperatures.
Category: Science calculators
Sources & methodology
This calculator applies the formula shown on this page exactly as written, using the standard definitions for its inputs. Results are computed from the values you enter — no data is stored — and are rounded only for display.
Content last reviewed by CalcHub Editorial.
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