Wavelength and Frequency Calculator
Enter a wavelength or a frequency and this calculator finds the other using the wave equation c = f x lambda, plus the photon energy E = h x f.
How to convert wavelength and frequency
- Choose whether you know the wavelength or the frequency.
- Enter the value and pick its unit.
- Read off the converted value and the photon energy.
Examples
Radio frequency to wavelength
f = 100 MHz
lambda = 2.998 m
Visible light wavelength to frequency
lambda = 500 nm
f = 5.996 x 10^14 Hz
Frequently asked questions
What is the wave equation?
The wave equation is c = f x lambda, where c is the wave speed, f is the frequency and lambda is the wavelength. In a vacuum c is the speed of light.
What speed of light is used?
The exact speed of light in a vacuum, 299,792,458 metres per second, is used as the default wave speed.
How is photon energy calculated?
Photon energy is E = h x f, where h is the Planck constant 6.626 x 10^-34 joule-seconds and f is the frequency in hertz. The result is in joules.
Which units are supported?
Wavelength in metres or nanometres, and frequency in hertz, megahertz or gigahertz. Values are converted to SI units before solving.
Why must the value be greater than zero?
Frequency and wavelength are inversely related, so a zero value would require dividing by zero, which is undefined and is rejected.
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