To convert wavelength to frequency enter the wavelength in microns (μm) and press "Calculate f and E". The corresponding frequency will be in the "frequency" field in GHz.

OR enter the frequency in gigahertz (GHz) and press "Calculate λ and E" to convert to wavelength. Wavelength will be in μm.

OR enter the energy in eV and click "Calculate λ and F" and the values will appear in the corresponding fields.

This chart shows wavelength in meters and frequency in hertz. By looking on the chart you may convert from wavelength to frequency and frequency to wavelength.
Frequency and wavelength of light are related to one another through the speed at which light travels.

Equation: f * λ = c
Equation: E = ^{hc}/_{λ}

where:
f = frequency in Hertz (Hz = ^{1}/_{sec})
λ = wavelength in meters (m)
c = the speed of light (299792458 ^{m}/_{s})
E = energy in electron Volts (eV)
h = Plank's constant (6.626068 × 10^{-34}^{m2kg}/_{s})