Photon energy calculator

Input
Output

eV

J

About this calculator

This calculator computes the energy of a photon from its vacuum wavelength λ\lambda, frequency ν\nu or wavenumber κ\kappa. The photon energy is

Ep=hν=hcλ=hcκE_{p} = h\nu = \dfrac{hc}{\lambda} = hc\kappa

where h6.6261034h \approx 6.626\cdot 10^{-34} is the Planck constant and cc is the speed of light in vacuum. Energy is converted to electronvolts by dividing it by the elemental charge e1.6021019e \approx 1.602 \cdot 10^{-19}.