Wavelength and Frequency Calculator

Convert between wavelength and frequency for light or sound.

Quick answer: Wavelength and Frequency Calculator: Convert between wavelength and frequency for light or sound. Everything runs in your browser, so nothing you enter is uploaded or stored.

Frequency (Hz)

Wave speed (m/s)

How to use Wavelength and Frequency Calculator

Enter your values in the fields.
The results update instantly as you type.
Note or copy the numbers you need.

Features

Instant results
Free, no signup
Runs in your browser, nothing is uploaded
Works on phone and desktop

Formula

wavelength = speed / frequency.

Worked example

A 100 MHz FM radio wave has a wavelength of about 3 m.

Frequently asked questions

What is the formula?

Wave speed = frequency x wavelength.

What speed should I use?

299,792,458 m/s for light, about 343 m/s for sound in air.

Is the Wavelength and Frequency Calculator free?

Yes. It is free, needs no signup and works on any device.