Gravitational Potential Energy Calculator
Calculate gravitational potential energy using PE = mgh. Enter mass, height, and gravity (default g = 9.81 m/s²).
GRAVITATIONAL PE
4,903.325 J
IN kJ
4.9033 kJ
IN ft⋅lbf
3,616.5062 ft⋅lbf
FORMULA
PE = mgh
Gravitational PE — Reference (g = 9.81 m/s²)
| Mass | 1 m | 10 m | 50 m | 100 m |
|---|---|---|---|---|
| 1 kg | 10 J | 98 J | 491 J | 981 J |
| 5 kg | 49 J | 491 J | 2,453 J | 4,905 J |
| 10 kg | 98 J | 981 J | 4,905 J | 9,810 J |
| 50 kg | 491 J | 4,905 J | 24,525 J | 49,050 J |
| 100 kg | 981 J | 9,810 J | 49,050 J | 98,100 J |
| 500 kg | 4,905 J | 49,050 J | 245,250 J | 490,500 J |
💡 How to Calculate Gravitational Potential Energy
What Is Gravitational Potential Energy?
Gravitational potential energy (PE) is the energy an object possesses because of its position in a gravitational field. The higher an object is above a reference point, the more gravitational PE it has stored. When the object falls, this potential energy converts into kinetic energy.
This principle is the basis for hydroelectric power generation, roller coasters, and many engineering applications. It is different from elastic potential energy, which is stored in deformed materials like springs.
How to Calculate Gravitational Potential Energy
Gravitational PE Formula
Where:
- PE = gravitational potential energy (J)
- m = mass of the object (kg)
- g = acceleration due to gravity (9.81 m/s² on Earth)
- h = height above the reference point (m)
Worked Example: Water Behind a Dam
1,000 kg of water held at a height of 100 meters behind a hydroelectric dam:
PE = 1,000 × 9.81 × 100 = 981,000 J = 981 kJ
This is enough energy to power a 100-watt light bulb for about 2.7 hours. In a real hydroelectric plant, millions of kilograms of water flow through turbines continuously, generating megawatts of power.
Conservation of Energy
When an object falls freely, gravitational PE converts entirely to kinetic energy (ignoring air resistance). At the bottom: KE = ½mv² = mgh. This means the velocity at the bottom is v = √(2gh), regardless of the object's mass. A ball dropped from 10 m hits the ground at v = √(2 × 9.81 × 10) = 14 m/s.