Calculate gravitational potential energy from mass, height and gravity, or the mass or height from the energy.
Last updated: November 8, 2026
PE = m × g × h
Gravitational potential energy is the energy an object has because of its height: • PE = m × g × h • m = PE ÷ (g × h), h = PE ÷ (m × g) • In free fall, impact speed v = √(2 g h) and time t = √(2h ÷ g) Example: lifting a 10 kg box 5 m gives it 10 × 9.81 × 5 ≈ 490 J of potential energy. Dropped, it falls in about 1.01 seconds and hits the ground at 9.9 m/s (22 mph). Fall speed and time ignore air resistance. Height is measured from whatever reference level you choose (the floor, a table).
Common questions about potential energy
PE = m × g × h. With mass in kg, height in m and g = 9.81 m/s², the result is in joules.
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In kilograms.
In metres.
Earth 9.81, Moon 1.62, Mars 3.72.