Wavelength Calculator — Sound Wave Length at Any Frequency

Wavelength determines how sound interacts with objects and room boundaries. A sound can only be effectively absorbed or diffused by an object that is at least a quarter of its wavelength. Bass frequencies (long wavelengths) are harder to treat than treble (short wavelengths).

Higher temperatures increase the speed of sound, which increases wavelength at a given frequency. At 20 degrees C the speed of sound is about 343 m/s. At 30 degrees C it is about 349 m/s — roughly a 2% increase.

An acoustic absorber must be at least one quarter of the wavelength thick to be effective. For example, to absorb 100 Hz (wavelength 3.43 m), you would need an absorber at least 86 cm deep.