Given below is the frequency to energy formula to calculate the energy of light from frequency. Energy (E) is defined in the form of photons. Light waves move through a vacuum at the same speed, the number of wave crests depends on the wavelength. That is the longer the photon's wavelength, the lower is its energy. Frequency to joules formula is defined as e = 6.626×10^{-34}×f, where f is the frequency and 6.626×10^{-34} is the Plank's Constant in Joules.

Frequency to energy formula is based on frequency and planck's constant (6.626×10^{-34}). Multiply frequency with planck's constant to find the energy of light in joules, KJ, eV or kcal.