Acoustic Wavelength Calculator

Convert frequency to acoustic wavelength and quarter wavelength at any air temperature. Free calculator for room acoustics and speaker design.

How the acoustic wavelength calculator works

Speed of sound in air is estimated from temperature (°C, °F, or K), then wavelength λ = c / f and quarter wavelength λ/4 are computed. Results can be shown in metres, millimetres, centimetres, inches, or feet.

Key terms

  • Wavelength (λ) - distance of one full cycle at a given frequency.
  • Quarter wavelength (λ/4) - common reference for absorber depth and port length limits.
  • Speed of sound - approximately 331.3 + 0.606 × T (°C) m/s in dry air.

Frequently asked questions

  • Why use quarter wavelength? Many porous absorbers and quarter-wave traps are tuned near λ/4 at the target frequency.
  • Can I enter frequency in kHz? Yes — select kHz for bass and mid calculations (e.g. 2 kHz = 2000 Hz).