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Frequency & Wavelength Calculator
Use the wave equation to solve one missing value: frequency, wavelength or propagation speed. Choose compatible units or a medium preset.
How do I calculate wavelength from frequency?
Use v = f × λ, where v is wave speed, f is frequency and λ is wavelength. To find wavelength, divide speed by frequency. For example, 300,000,000 m/s ÷ 100,000,000 Hz = 3 m. Enter any two values and leave the third blank.
Frequently asked questions
How do I calculate wavelength from frequency?
Use v = f × λ, where v is wave speed, f is frequency and λ is wavelength. To find wavelength, divide speed by frequency. For example, 300,000,000 m/s ÷ 100,000,000 Hz = 3 m. Enter any two values and leave the third blank.
Are my values uploaded?
No. The calculation runs in this browser; entered values are not uploaded or saved by this tool.
What is the wave equation?
For a traveling wave, speed v equals frequency f multiplied by wavelength λ. If you know any two positive values, you can calculate the third, provided all quantities describe the same wave in the same medium.
Does the speed of every wave equal the speed of light?
No. Light speed depends on the material, while sound and other waves have their own speeds. The presets are approximate optical light-speed examples only; choose Custom and enter a suitable speed for other cases.
Can I use this as an antenna design calculator?
It only calculates the basic frequency–wavelength–speed relationship. Antenna length also depends on antenna geometry, feed, surroundings and a shortening factor, so this tool does not predict an antenna’s final physical length.