Photoelectric Effect Calculator
Calculate the maximum kinetic energy of photoelectrons ejected from a metal surface, based on Einstein’s photoelectric effect equation.
What the photoelectric effect is
The photoelectric effect occurs when light shining on a material ejects electrons from its surface, but only if the light’s photon energy exceeds the material’s work function — the minimum energy needed to free an electron.
The formula
Photon energy E = hc/λ, where h is Planck’s constant, c is the speed of light, and λ is the light’s wavelength. Maximum photoelectron kinetic energy is KEmax = E − φ, where φ is the material’s work function. If photon energy is less than the work function, no electrons are emitted regardless of light intensity, a key discovery that helped establish quantum theory.
This calculator is intended for general physics education and reference.