Kinetic Energy Calculator
Calculate kinetic energy KE = ½mv² and momentum p = mv. Enter mass (kg) and speed (m/s) for instant results in Joules.
How to use this tool
- Enter mass and speed in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your kinetic energy and the full breakdown beneath it.
Kinetic energy is the energy of motion: KE = ½mv², where m is mass in kilograms and v is speed in metres per second. The result is in Joules (J). Momentum is p = mv (kg·m/s).
Frequently asked questions
- Why does speed have a larger effect than mass?
- Because speed is squared. Doubling mass doubles KE; doubling speed quadruples it.
- How do I convert km/h to m/s?
- Divide by 3.6. For example, 90 km/h = 25 m/s.