Gravitational potential energy calculator
Calculate gravitational potential energy (E = m·g·h) and the speed the body would reach if it fell.
Gravitational potential energy is the energy "stored" by height. As it falls, it becomes kinetic energy — hence the estimated speed.
How the calculation works
Gravitational potential energy is E = m · g · h, with mass in kg, gravity in m/s² (9.8 on Earth) and height in meters. The result is in joules (J). In a fall, all of it becomes kinetic, and the speed is v = √(2·g·h).
Examples
- A 5 kg object at 3 m height: 5 × 9.8 × 3 = 147 J.
- Falling 3 m, it hits the ground at v = √(2×9.8×3) ≈ 7.7 m/s.
Frequently asked questions
Does potential energy depend on the path?
No. It only depends on the final height relative to the reference point, not the path taken.
Where is height measured from?
From a reference you choose (floor, table…). What matters physically is the height difference, not the absolute value.
Does it change on the Moon?
Yes. Lunar gravity is ~1.6 m/s², so the same mass and height have ~6× less potential energy.
Do heavier objects fall faster?
Not in a vacuum. Fall speed is v = √(2gh), independent of mass. Air resistance creates the opposite impression.
Does potential energy depend on my reference point?
Yes, it is always relative to a chosen reference level. Only the height difference matters.
Why is the real value lower than calculated?
Because friction and air resistance turn part of the energy into heat. The formula gives an upper bound.
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Updated on June 30, 2026 · by Rafael Rossi · Methodology & sources