Kinetic Energy Calculator

Compute the kinetic energy and momentum of a moving object.

Inputs

kg
m/s
Formulas
KE = ½·m·v²
p = m·v

Results

Kinetic energy J
Momentum kg·m/s

What is kinetic energy?

Kinetic energy is the energy an object possesses because of its motion. Any object with mass moving at some speed carries kinetic energy, given by KE = ½mv². The energy grows linearly with mass but with the square of speed, so doubling the speed quadruples the kinetic energy.

KE = ½·m·v²

Kinetic energy and momentum

Momentum, p = mv, is a closely related quantity that also describes motion but is a vector and scales linearly with speed. Together they govern collisions: momentum is conserved in every collision, while kinetic energy is conserved only in perfectly elastic ones.

Enter a mass in kilograms and a velocity in metres per second to obtain both the kinetic energy in joules and the momentum.

Frequently asked questions

Why does speed matter more than mass?

Kinetic energy depends on the square of velocity, so velocity has a much stronger effect. Doubling speed multiplies kinetic energy by four, while doubling mass only doubles it.

Can kinetic energy be negative?

No. Mass is positive and velocity is squared, so kinetic energy is always zero or positive.

Read the full guide