Kinetic Energy Calculator

Use KE = ½mv² to calculate joules, kilojoules, and watt-hours from common mass and speed units.

Mass

Speed

—J

—kJ

—Wh

—ft·lbf

—KE = ½mv²

These are idealized classical-physics calculations. Real systems can differ because of air resistance, friction, deformation, measurement uncertainty, non-constant forces, or other effects not included in the selected model.

How to use this Kinetic Energy Calculator

Calculate translational kinetic energy from mass and speed. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.