Photon Energy, Wavelength, and Frequency Calculator

Enter either photon energy, wavelength, or frequency of electromagnetic radiation and calculate the other two. Wavelength is assumed to be in vacuum.

A photon's energy is equal to its frequency multiplied by the Planck constant (6.62607015 × 10-34 J/Hz). Frequency multiplied by wavelength equals the speed of light (299792458 m/s). An electronvolt is a small unit of energy commonly used in particle physics; it is equal to 1.602176634 × 10-19 joules. To enter a number in scientific notation, use e-notation: enter 6.022 × 1023 as 6.022e23, and 6.626 × 10-34 as 6.626e-34.