Photoelectric Effect Calculator

About this calculator

This calculator applies Einstein's photoelectric equation, KE_max = hf − φ (or equivalently hc/λ − φ), to find the maximum kinetic energy of electrons ejected from a metal surface when struck by light. Here h is Planck's constant, f is the photon frequency (c/λ for wavelength λ), and φ is the material's work function — the minimum energy needed to free an electron from the metal. If the photon energy is below the work function, no electrons are emitted regardless of light intensity, which is the key evidence for light's particle nature.

Physics students and instructors use it to work through Einstein's 1905 Nobel-winning explanation of the photoelectric effect, verifying threshold frequency and stopping potential problems from textbooks. Enter the photon wavelength (or frequency) and the material's work function to get the maximum electron kinetic energy.