Wavelength Calculator

Use our wavelength calculator to find a wave’s length given its frequency and velocity.




Wavelength Formula

λ = 𝑣 / 𝑓
Learn how we calculated this below

scroll down

How to Calculate Wavelength

Wavelength is the distance between consecutive crests (or troughs) in a wave. This distance is a key determinant of the wave’s characteristics, such as its color in the case of light or its pitch in the case of sound.

Wavelength is typically measured in meters (m), but depending on the wave’s frequency and nature, it might also be expressed in centimeters (cm), millimeters (mm), or even nanometers (nm) for extremely small waves like those of light.

Wavelength Formula

The relationship between wavelength, wave velocity (the speed at which a wave propagates through a medium), and frequency (the number of wave cycles that pass a fixed point per second) is a cornerstone of wave physics. The formula that connects these three variables is:

λ = 𝑣 / 𝑓

λ = wavelength
𝑣 = wave velocity or speed
𝑓 = wave frequency

Thus, the wavelength λ is equal to the wave’s velocity 𝑣 divided by its frequency 𝑓.

Graphic showing the wavelength formula where the length of a wave is equal to its velocity divided by its frequency.

For example, suppose you need to determine the wavelength of a sound wave traveling through air.

The velocity of sound in air, under standard conditions, is approximately 343 meters per second (m/s). If the sound has a frequency of 256 Hertz (Hz), we can use the wavelength formula to find the wavelength.

λ = 343 m⁄s / 256 Hz = 1.34 m

So, the distance between consecutive crests of this sound wave is equal to about 1.34 meters.