Potential Energy Calculator
Gravitational potential energy is stored purely by virtue of height — lift something up and you've done work against gravity, and that work is recoverable as kinetic energy on the way back down.
Inputs
Result
196.2 J
How it works
PE = m g h
How the potential energy calculator works
PE = m × g × h, where g is gravitational acceleration and h is height above the reference point.
Worked example: 2 kg mass at 10 m height
- PE = 2 × 9.81 × 10 = 196.2 J.
- On the Moon (g ≈ 1.62 m/s²) instead, the same mass and height would give PE = 2 × 1.62 × 10 = 32.4 J — far less, because gravity itself is weaker there.
Common mistakes to avoid
Forgetting height is always relative to a chosen reference point
Potential energy has no single absolute value — it depends entirely on where you define h = 0. Comparing PE between two setups only makes sense if both use the same reference height.
Using the wrong gravity value for the context
This calculator lets gravity be entered directly, which matters for anything other than Earth's surface — using 9.81 m/s² for a Moon or Mars calculation gives a badly wrong answer for that context.
Frequently asked questions
Why does potential energy depend on where you set the reference height?
Only changes in potential energy have real physical meaning (like the energy released falling from one height to another) — the absolute value is a bookkeeping choice, and any consistent reference point works as long as it's used consistently.
How does this convert into kinetic energy when something falls?
In free fall (ignoring air resistance), potential energy lost exactly equals kinetic energy gained — this is the core idea used in the Free Fall Calculator to derive impact speed from height alone.
What if gravity varies with altitude in a very tall structure?
This formula assumes constant g, which is an excellent approximation for everyday heights but becomes less accurate over very large altitude changes, like satellite orbits, where gravity itself measurably weakens with distance.
Can potential energy be negative?
Yes, relative to a chosen reference point — an object below the reference height (like an object at the bottom of a well relative to ground level) has negative potential energy in that reference frame.
Related calculators
Kinetic Energy Calculator
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Free Fall Calculator
Fall time and impact speed from a height.
Energy Calculator
Mass-energy equivalence and total mechanical energy.
Work Done Calculator
Mechanical work from force, distance and angle.
Escape Velocity Calculator
Speed needed to escape a body's gravity.