Sound Wavelength Calculator (λ = v/f)
Sound waves have a physical size, and it matters for everything from room acoustics to speaker design. Concert A (440 Hz) has a wavelength of about 78 cm in room-temperature air. This calculator finds the wavelength for any frequency in air (temperature-adjusted), water, steel, or a custom medium.
The Formula
lambda = v / f
Wavelength (lambda) equals the speed of sound divided by frequency. Higher frequencies mean shorter wavelengths. A 20 Hz bass note has a wavelength of 17 meters, while a 20,000 Hz tone is just 1.7 centimeters.
Speed of Sound in Air
The speed of sound in air increases with temperature: v = 331.3 + 0.606 x T (in Celsius).
| Temperature | Speed of Sound |
|---|---|
| -10 C (14 F) | 325 m/s |
| 0 C (32 F) | 331 m/s |
| 20 C (68 F) | 343 m/s |
| 30 C (86 F) | 349 m/s |
| 40 C (104 F) | 355 m/s |
Speed of Sound in Different Media
| Medium | Speed | Notes |
|---|---|---|
| Air (20 C) | 343 m/s | Varies with temperature |
| Water | 1,480 m/s | About 4.3x faster than air |
| Concrete | 3,400 m/s | Varies by composition |
| Steel | 5,960 m/s | About 17x faster than air |
| Diamond | 12,000 m/s | Fastest common material |
Why Wavelength Matters
- Room acoustics: A room can only support standing waves for sounds with wavelengths shorter than twice the room dimension. Small rooms struggle with bass below ~80 Hz.
- Speaker design: A speaker driver is most effective for wavelengths close to its diameter.
- Noise barriers: To block sound, a barrier must be several wavelengths thick at the target frequency.