Energy Units

Energy or force is a physical quantity that is a single measure of the various forms of motion and interaction of matter, a measure of the transition of matter from one form to another.

Energy is a measure of the ability of a physical system to perform work, so quantitatively energy and work are expressed in the same units.

International System of Units (SI)

In the international system of units (SI), energy is measured in Joules [J], and in the GHS system in other units.

Joule is equal to the work done when moving the point of application of force equal to one newton, at a distance of one meter in the direction of the force.

• 1 kJ = 1000 J.
• 1 MJ = 1000 kJ.

Non-SI metric units

• 1 Megacalorie [Mcal] = 4186800 J.
• 1 Kilocaloria [kcal] = 4186.8 J.
• 1 Calories [cal] = 4.1868 J.
• 1 Kilogram of force per meter [kgf·m] = 9.80665 J.
• 1 Kilowatt per hour [KW·h] = 3600 kJ.
• 1 Watt per hour [W·h] = 3600 Joules.
• 1 Watt per second [W·s] = 1 J.
• 1 Erg [erg] = 1 g·cm²/s = 10-7 J.

United States and Britain

In the United States and Britain, the following units are also used to measure energy:

• Term (EU and USA) = 105506000 J.
• Term (USA) = 105480400 J.
• Term (Britain) = 105505585.257348 J.
• BTU (British Thermal Unit) = 1055.056 J.
• MMBTU = 1000000 BTU.
• Pound of force per foot [ft·lb] = 1.3558179483314 J.