Boneyard Tools

Sound Wavelength and Period Calculator

Enter a frequency to find the wavelength of sound in air and the period of one cycle. The speed of sound is taken from the air temperature you choose, or you can enter a speed of sound directly.

How to use the sound wavelength calculator

  1. Enter the frequency in hertz, for example 440.
  2. Set the air temperature in Celsius, or enter a speed of sound directly.
  3. Read the wavelength in metres and the period of one cycle in milliseconds.

Examples

A4 at room temperature

440 Hz, 20 C
speed 343.2 m/s, wavelength 0.78 m, period 2.27 ms

Low bass note

20 Hz, 20 C
wavelength about 17.16 m

Frequently asked questions

How is the wavelength of sound calculated?

Wavelength equals the speed of sound divided by the frequency. At 20 C the speed of sound in air is about 343 metres per second, so 440 Hz has a wavelength near 0.78 metres.

How does temperature change the speed of sound?

The speed of sound in dry air is about 331.3 times the square root of (1 + temperature in Celsius / 273.15) metres per second. Warmer air carries sound faster.

What is the period of a sound?

The period is the time for one full cycle, equal to 1 divided by the frequency. The calculator shows it in milliseconds, so 440 Hz has a period of about 2.27 ms.

Can I set the speed of sound myself?

Yes. Enter a speed of sound directly and it overrides the temperature estimate, useful for water, other gases or a value from a measurement.

Why do low frequencies have such long wavelengths?

Wavelength is inversely proportional to frequency, so a 20 Hz tone spans about 17 metres in air. That is why bass is hard to control and needs large room treatment.

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