Energy units
Physicists measure energy in joules, because a joule is based entirely on metric units
Here are some other energy units for comparison:
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 This is an old outdated unit. (show 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" (which would be 8,368,000 joules). (show formal definition of unit)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.