Energy & Work Converter
Convert joules, calories, kilowatt-hours, BTU and electronvolts.
This is the unit written as "Calories" on nutrition labels.
1 kilojoule equals 0.239006 kilocalories
About energy units
Energy is measured in joules in SI. Nutrition uses kilocalories, electricity billing uses kilowatt-hours, heating uses BTU and particle physics uses electronvolts. Select the definition specified in the source: calorie and therm variants do not all have the same value.
Calories here are thermochemical (4.184 J), while BTU uses the International Table definition. A kilowatt-hour is energy (3.6 MJ), not power; a food Calorie is a kilocalorie.
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Compare unit values in the base unit. Numbers are rounded to 8 significant digits; conventions and assumptions appear beside the units.
| Unit | Symbol | 1 unit in J |
|---|---|---|
| joule | J | 1 |
| kilojoule | kJ | 1,000 |
| megajoule | MJ | 1,000,000 |
| gigajoule | GJ | 1,000,000,000 |
| watt-hour | Wh | 3,600 |
| kilowatt-hour | kWh | 3,600,000 |
| megawatt-hour | MWh | 3,600,000,000 |
| calorieThis is the small calorie. The "Calorie" on food labels is a kilocalorie, which is 1,000 of these. | cal | 4.184 |
| kilocalorieThis is the unit written as "Calories" on nutrition labels. | kcal | 4,184 |
| International Table calorie | cal_IT | 4.1868 |
| British thermal unitSeveral BTU definitions exist. This converter uses the International Table BTU, the one used by HVAC equipment ratings. | BTU | 1,055.0559 |
| thermTherm definitions differ. This is therm (US), not therm (EC) or 100,000 International Table BTU. | thm | 105,480,400 |
| foot-pound forceEnergy and torque share these dimensions. For fastener torque see the Torque category, where the same quantity is written lbf·ft. | ft·lbf | 1.3558179 |
| electronvolt | eV | 1.6021766e-19 |
| erg | erg | 0.0000001 |
| ton of TNTA defined convention, not a measurement of any particular batch of TNT. | tTNT | 4,184,000,000 |
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