Energy Converter
Convert between 8 energy units.
Supported Units
| Unit | Symbol | Description |
|---|---|---|
| joules | J | SI unit of energy. |
| kilojoules | kJ | 1,000 Joules. |
| calories | cal | Chemistry calorie (small). |
| kilocalories | kcal | Food Calorie (large). |
| kilowatt-hours | kWh | Electricity billing unit. |
| BTU | BTU | British Thermal Unit. |
| watt-hours | Wh | Small battery energy unit. |
| electronvolts | eV | Atomic scale energy. |
All Energy Converters
kilojoules to…
calories to…
kilocalories to…
kilowatt-hours to…
watt-hours to…
electronvolts to…
About Energy Conversions
Energy conversion is where physics meets nutrition and billing. The same concept—energy—is measured in Joules (science), Calories (food), Kilowatt-hours (electricity), and BTUs (heating). It's easy to get lost. A 'Calorie' on a food label is actually a kilocalorie (1,000 chemistry calories). Your electricity bill charges you for kWh, which is 3.6 million Joules. Our converter untangles these units so you can compare an apple's energy to a battery's charge. Common conversions: 1 kcal = 4.184 kJ, 1 kWh = 3.6 MJ, and 1 BTU ≈ 1,055 Joules.