Enter the speed of light, length, width, and height of the cavity into the calculator to determine the resonance frequency. This calculator can also evaluate any of the variables given the others are known.

Cavity Resonance Formula

The following formula is used to calculate the resonance frequency of a cavity resonator.

f = c / (2 * √(L * W * H))


  • f is the resonance frequency (Hz) c is the speed of light (m/s) L is the length of the cavity (m) W is the width of the cavity (m) H is the height of the cavity (m)

To calculate the resonance frequency, first calculate the product of the length, width, and height of the cavity. Take the square root of this product. Then, divide the speed of light by twice this value. The result is the resonance frequency.

What is a Cavity Resonance?

Cavity resonance refers to the phenomenon where waves, such as sound or electromagnetic waves, resonate or build up in intensity within a specific physical space or cavity due to constructive interference. This occurs when the wavelength of the wave matches the dimensions of the cavity, causing the wave to reflect back and forth, reinforcing itself. This principle is used in various applications, such as in musical instruments, microwave ovens, and lasers.