Kinetic Energy Calculator
The energy of motion, from mass and velocity.
The square is the story
KE = ½ × m × v²
Energy grows with the SQUARE of speed: a car at 100 km/h carries four times the energy it had at 50, and needs four times the braking distance. Every road-safety statistic about speed traces back to this equation.
Where the energy goes
A 1,500 kg car at 25 m/s carries about 469 kJ, the energy of 130 watt-hours: roughly a laptop battery, all of which the brakes must turn into heat to stop. Regenerative braking in EVs recovers a good fraction of it instead.