Wavelength ↔ Frequency Converter
Convert between wavelength and frequency for light and sound waves
Calculator
f = c / λ = 3.00e+8 / 5.00e-7 = 5.9958e+14 Hz
Visible Light
500 nm is in the visible spectrum
Wave Equation
- c = f × λ (wave speed = frequency × wavelength)
- f = c / λ (frequency = speed / wavelength)
- λ = c / f (wavelength = speed / frequency)
- Speed of light: 299,792,458 m/s
- Speed of sound: ~343 m/s (in air at 20C)
How to Use
Convert between wavelength and frequency for electromagnetic waves
Choose wave type
Select light (electromagnetic) or sound waves
Enter value
Input either wavelength or frequency in your preferred units
Get conversion
See the converted value with appropriate units and visible spectrum indicator
Wave Equation
wavelength = c / f or f = c / wavelength
Wavelength times frequency equals wave speed. For light, c = speed of light.
Frequently Asked Questions
Wavelength and frequency are inversely proportional through the wave equation: wavelength = wave speed divided by frequency. For light, the speed is constant at 3x10^8 m/s. Higher frequency means shorter wavelength, and vice versa.
The speed of light in a vacuum is exactly 299,792,458 meters per second (approximately 3x10^8 m/s). This is a fundamental constant of nature. For sound waves, the speed depends on the medium - about 343 m/s in air at room temperature.
Visible light spans wavelengths from about 380nm (violet) to 700nm (red). Our calculator shows the visible spectrum color for light wavelengths. Frequencies range from about 430 THz (red) to 790 THz (violet).
Use the same formula for all electromagnetic radiation. Radio waves have frequencies in kHz to GHz (wavelengths in meters to kilometers), while visible light is in THz (wavelengths in nanometers). Our calculator handles all ranges with appropriate unit conversions.