Wavelength to Frequency Converter

Convert wavelength to frequency using the speed of light. Enter a wavelength in nm, um, mm, cm, or m and get Hz, MHz, GHz, and THz.

Independently verified for accuracy

Calculator by Toolsloft ↗
THz
599.584916
GHz
599584.916
MHz
599584916
Hz
599,584,916,000,000

Convert the wavelength of light or a radio wave to its frequency in a vacuum. Enter a wavelength in meters down to nanometers and get the frequency in Hz, MHz, GHz, and THz. Handy for optics, antenna work, and physics problems.

How this is calculated

For a wave in a vacuum, frequency equals the speed of light divided by wavelength, f = c / lambda. This uses the exact defined speed of light, c = 299792458 m/s, after converting the entered wavelength to meters.

How to use

  1. Enter the wavelength value.
  2. Choose the wavelength unit.
  3. Read the frequency in Hz, MHz, GHz, and THz.

Examples

  • Green light: 500 nm = 599.6 THz
  • Radio: 3 m = 99.93 MHz

FAQ

What speed of light does this use?
The exact defined value in a vacuum, 299,792,458 meters per second. In a material such as glass or water the wave travels slower, so the frequency would differ.
What is the formula?
Frequency equals the speed of light divided by wavelength. Shorter wavelengths give higher frequencies.
Can I go the other way?
Yes, wavelength equals the speed of light divided by frequency. This tool handles the wavelength-to-frequency direction.

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