Sound Wavelength Calculator and Audio Frequency Chart
Convert frequency to sound wavelength in air, water and steel. Includes audio wavelength chart for common frequencies.
Sound wavelength determines how sound interacts with objects and spaces. The formula is wavelength = speed of sound / frequency. In air at 20°C (343 m/s), a 440 Hz tone (A4) has a wavelength of about 78 cm - roughly the width of a doorway. Low frequencies have long wavelengths that bend around obstacles, while high frequencies have short wavelengths that are easily blocked. This is why bass passes through walls but treble does not. The chart below covers common audio frequencies from 20 Hz (subwoofer territory) up to 20 kHz (the upper limit of human hearing).
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Frequently asked questions
In air at 20°C: 20 Hz = 17.15 m, 50 Hz = 6.86 m, 100 Hz = 3.43 m, 250 Hz = 1.37 m, 440 Hz (A4) = 0.78 m, 1 kHz = 34.3 cm, 2 kHz = 17.15 cm, 5 kHz = 6.86 cm, 10 kHz = 3.43 cm, 20 kHz = 1.72 cm. Each octave halves the wavelength.
Wavelength = 343 / 440 = 0.7795 m (77.95 cm). This is the standard tuning pitch A4, used as the reference for tuning musical instruments and the basis for the chart above.
Human hearing spans 20 Hz to 20 kHz. In air, that is 17.15 m (20 Hz - longer than a city bus) down to 1.72 cm (20 kHz - smaller than your thumb). Concert hall acoustics must handle this 1000:1 wavelength range.
Low frequencies have long wavelengths. A 50 Hz bass note has a 6.86 m wavelength - much larger than wall thickness. Waves much larger than obstacles bend around them. High frequencies (short wavelengths) are absorbed or reflected, which is why you hear muffled bass through a wall but not the vocals.
Air: 343 m/s at 20°C (changes ~0.6 m/s per °C), water: 1480 m/s (4.3× faster), steel: 5960 m/s (17.4× faster). Sound travels faster in denser, stiffer materials. A 440 Hz tone has wavelength 78 cm in air, 3.36 m in water and 13.5 m in steel.