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Science & Engineering

Kinetic Energy Calculator

Calculate kinetic energy from mass and velocity, or solve for velocity or mass from a known energy.

Your inputs

Results

Kinetic energy

200,000 J

In kilojoules
200 kJ
Speed in km/h
72

✓Exact calculation — rounded only for display

What this calculator does

Kinetic energy is the energy of motion; it grows with the square of speed.

Formula and method

KE = ½ m v²; v = √(2KE ÷ m); m = 2KE ÷ v²

Worked example

Calculated by this tool with its default inputs:

Inputs

  • Solve for: Kinetic energy
  • Mass: 1000 kg
  • Velocity: 20 m/s

Results

  • Kinetic energy: 200,000 J
  • In kilojoules: 200 kJ
  • Speed in km/h: 72

How to read the results

Doubling speed quadruples kinetic energy — why stopping distances grow so fast.

Assumptions and limitations

  • Non-relativistic (speeds far below light).

These are educational estimates. Electrical, structural and other safety-critical work must comply with local codes and be designed or checked by a qualified professional.

Questions

Does direction matter?

No — kinetic energy depends on speed, not direction.

Sources

Methodology and verification

Result type
Exact mathematical calculation (rounded only for display)
Formula version
1.0
Automated verification
4 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
Editorial review
Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.

Privacy

Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Inputs are added to a share link only if you choose to include them. Privacy policy