This calculator finds the gravitational potential energy of an object raised to a height near a planet's surface. The standard gravity g is filled in automatically, but you can change it for other planets.
What the symbols mean
- E — potential energy (joules).
- m — mass (kilograms).
- g — gravitational acceleration, 9.81 m/s² at Earth's surface (auto-filled).
- h — height above the reference level (metres).
Worked example
Lifting a 2 kg book to a shelf 1.8 m high stores 2 × 9.81 × 1.8 ≈ 35 J of potential energy.
How the formula works
Gravitational potential energy is the energy an object has because of its height in a gravitational field. Lifting an object stores energy in it; letting it fall releases that energy as motion. The formula multiplies the object's weight (mass times g) by the height it has been raised. It applies near a planet's surface, where g is roughly constant.
Common mistakes to avoid
- Forgetting to choose a reference height. Potential energy is always measured relative to some chosen zero level.
- Using the wrong g. Near Earth g is about 9.81 m/s²; on the Moon it is far smaller.
Where it is used
Potential energy explains hydroelectric dams, roller coasters, pendulums, and any situation where height converts to and from motion. It pairs with kinetic energy through the conservation of energy.