The potential energy calculator computes gravitational potential energy using PE = mgh — mass × gravity × height. Calculate the stored energy of any elevated object in Joules (metric) or foot-pounds (imperial). Supports Earth, Moon, and Mars gravity presets.
Potential Energy Calculator
How to Use the Potential Energy Calculator
This potential energy calculator computes gravitational potential energy using PE = mgh. The result represents how much work was done lifting the object to its current height — energy that will convert to kinetic energy when the object falls.
Step 1: Enter Mass and Height
Enter the object's mass in kg (metric) or lb (imperial) and its height above the reference point in meters or feet. Height can be negative if the object is below the reference level.
Step 2: Set Gravitational Acceleration
Use the preset buttons for Earth (9.81 m/s²), Moon (1.62 m/s²), or Mars (3.72 m/s²), or enter any custom value. Earth's surface gravity is 9.81 m/s² at sea level.
Worked Examples
Roller coaster: A 500 kg roller coaster car at the top of a 40 m hill: PE = 500 × 9.81 × 40 = 196,200 J = 196.2 kJ. This all converts to kinetic energy at the bottom.
Moon vs. Earth: A 10 kg rock at 10 m height on Earth has PE = 10 × 9.81 × 10 = 981 J. The same rock on the Moon has PE = 10 × 1.62 × 10 = 162 J — about 16.5% of Earth's value.
FAQ
What is gravitational potential energy?
Gravitational potential energy (GPE) is the energy stored in an object due to its height above a reference point. The formula is PE = mgh, where m is mass (kg), g is gravitational acceleration (9.81 m/s² on Earth), and h is height (m). A 10 kg rock at 5 m height has PE = 10 × 9.81 × 5 = 490.5 J.
Can I use a different gravity value?
Yes. This calculator lets you specify any gravitational acceleration value. Earth's surface gravity is 9.81 m/s², the Moon's is 1.62 m/s², and Mars is 3.72 m/s². Use these values for multi-body problem sets.
Is this calculator free?
Yes, completely free with no signup required. All calculations run in your browser.
Is my data private?
Yes. Everything runs locally in your browser. No data is transmitted.
What is the imperial unit for energy?
In imperial units, energy is measured in foot-pounds (ft-lb). 1 foot-pound = 1.35582 Joules. The gravitational constant in imperial is 32.174 ft/s². A 10 lb object at 4 ft height has PE = 10 × 32.174 × 4 / 32.174 = 40 ft-lb (using weight × height directly in imperial).