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Energy Calculator — Kinetic, Potential and E = mc²

Work out kinetic, potential or mass–energy — or solve backwards for mass, speed or height.

  • Free
  • No sign-up
  • Nothing is sent or stored
Formula
kg
m/s

Result

Kinetic energy
200,000 J
Mass (m)
1,000 kg
Velocity (v)
20 m/s
How it was calculated
  1. KE = ½ × m × v²
  2. KE = 200,000 J
1 kWh = 3,600,000 J and 1 kcal = 4,184 J.

The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved.

How to use the Energy Calculator

  1. Choose kinetic, potential or mass–energy.
  2. Pick what to solve for.
  3. Enter the known values and read the energy in joules.

What does this tool do?

Kinetic energy is the energy of motion, ½mv² — doubling speed quadruples it. Gravitational potential energy is mgh, the energy stored by lifting something.

Einstein's E = mc² shows that mass itself is a form of energy: one gram of mass is equivalent to about 9 × 10¹³ joules.

Why use it?

  • Three energy types.
  • Solve for any variable.
  • Scientific notation for very large values.

The formula

KE = ½mv²
PE = mgh
E = mc²

Accuracy and limits

  • Values are in SI units (shown next to each field). Convert other units first, or use our unit converters.

Privacy

The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved. There's no account to create and nothing to install.

Last reviewed by the M2Toolkit team.

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