Why does wavelength matter in audio?

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).

How does temperature affect wavelength?

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.

What is the quarter wavelength rule?

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.

AudioCalcs

Wavelength Calculator — Sound Wave Length at Any Frequency

Calculate the wavelength of a sound wave at any frequency and temperature.

Frequency

Temperature

How We Calculate This

Wavelength = Speed of Sound / Frequency

Speed of Sound = 331.3 + 0.606 × Temperature (°C)

At 20°C the speed of sound is approximately 343.2 m/s. A 1 kHz tone has a wavelength of about 34 cm, while 100 Hz has a wavelength of about 3.43 m.

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Last updated: February 2026

All calculations are estimates based on standard formulas. Always verify results for critical applications.