Frequency to wavelength calculator
Enter the frequency and its unit to get the wavelength in meters and centimeters. Handy for radio amateurs, network technicians and students.
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How to use it
- Enter frequency and unit.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
λ = c / f with c = 299792458 m/s, then the half wave λ / 2 and quarter wave λ / 4.
Example
Inputs: Frequency = 2.4, Unit = gigahertz (GHz). Result: Wavelength: 0.124914 m; Wavelength in cm: 12.4914 cm; Half wavelength: 0.062457 m.
Limits and caveats
- Values are for vacuum, which air matches closely. A real antenna is cut a little shorter because of velocity factor and end effects.
Questions about this tool
What is the wavelength of 2.4 GHz Wi-Fi?
About 12.5 cm, and a quarter of it is roughly 3.1 cm.
Why does the quarter wavelength matter?
A quarter-wave antenna over a ground plane is one of the simplest and most common antenna designs.
Can I use it for sound waves?
No, it uses the speed of light. For sound use the wave speed calculator with the speed of sound.