Energy units
Energy/units
Physicists measure energy in joules, because a joule is based entirely on metric units
Unit | Joules | Note |
---|---|---|
watt second | 1 | Electrical power is often measured in watts. A watt is the same as 1 joule per second. |
calorie (lowercase) | 4 | This is not the unit for measuring food. This is an old outdated unit. Formal definition: The amount of energy needed to heat 1 gram of water up by 1 degree Celsius. |
kilojoule | 1,000 | |
BTU | 1,055 | British Thermal Unit (used for heating, typically). |
watt hour | 3,600 | Used in battery specs. |
kalorie kcal kilocalorie Calorie (uppercase) |
4,184 | This is the unit used for measuring food energy - for example, "A diet of 2000 Calories". Formal definition: The amount of energy needed to heat 1 kilogram of water up by 1 degree Celsius. |
megajoule | 1,000,000 | |
kilowatt hour | 3,600,000 | Used on electricity bills. |
gallon gasoline | 131,881,980 | The amount of energy you'd get from burning 1 gallon of gasoline. |
gigajoule | 1,000,000,000 | Enough energy to power a house for a week or two. |
terajoule | 1,000,000,000,000 | |
petajoule | 1,000,000,000,000,000 | Enough energy to power 32,000 homes for a year. |
Mtoe | 41,868,000,000,000,000 | The energy in 1 million tons of crude oil. |
exajoule | 1,000,000,000,000,000,000 | |
quad | 1,055,055,900,000,000,000 | A quadrillion BTU (see unit defined above) |
CMO | 160,000,000,000,000,000,000 | Cubic mile of oil. This is approximately how much energy the world uses in every 3 to 4 months. |
If you want to do more conversions or calculations, you can use the calculator.