Kinetic Energy Calculator

Kinetic Energy Formula

Worked Example

A 20 kg object moving at 10 m/s:

1. KE = ½ × m × v²
2. KE = ½ × 20 × 10²
3. KE = 1000 J

In MJ: 0.001 MJ · In cal: 239.0057361 cal · In kcal: 0.2390057361 kcal · In Wh: 0.2777777778 Wh · Momentum p = mv: 200 kg·m/s

Work–energy theorem

The net work done on a body equals its change in kinetic energy. To stop the 20 kg object, friction must do 1000 J of work, for example 100 N over 10 m.

More Energy, Work and Momentum Calculators

• Potential Energy Calculator

  PE = m g h

  PE potential energy (J), m mass, g gravitational acceleration, h height above the reference level

  Example: Lifting a 10 kg box 10 m on Earth: Potential energy PE = 980.665 J.

  Open the potential energy calculator →

• Work Calculator

  W = F d cos θ

  W work (J), F force, d displacement, θ angle between force and motion

  Example: Pulling a sled 10 m with 50 N at 60° to the ground: Work W = 250 J.

  Open the work calculator →

• Momentum Calculator

  p = m v

  p momentum (kg·m/s), m mass, v velocity (a vector: its sign gives the direction)

  Example: A 1.5 kg ball moving at 20 m/s: Momentum p = 30 kg·m/s.

  Open the momentum calculator →

• Power Calculator

  P = W / t

  P power (W), W work or energy transferred (J), t time (s)

  Example: Doing 15,000 J of work in 60 seconds: Power P = 250 W.

  Open the power calculator →

Frequently asked questions

Sources

• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures .

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.