Kinetic Energy Calculator

Calculate kinetic energy from mass and speed with E = ½mv², in joules, with a worked example and the classical-mechanics limits.

Calculator

Kinetic energy125 J

Method, variables and units

Kinetic Energy Calculator

Formula: E_k = 1/2 m v^2

  • E_k — kinetic energy (J)
  • m — mass (kg)
  • v — speed (m/s)

Assumption: The calculation uses classical mechanics.

Worked example

Kinetic Energy Calculator

A 10 kg object moving at 5 m/s has 125 J of kinetic energy.

Important limits

  • Kinetic Energy Calculator: At speeds close to the speed of light, relativistic effects must be used instead.