Energy units explained
| Unit | Symbol | Definition |
|---|---|---|
| Joule | J | The joule is the SI unit of energy: the work done by a force of one newton over one meter. |
| Kilojoule | kJ | A kilojoule is 1,000 joules, used on food labels in Australia and Europe. |
| Calorie (small) | cal | A (thermochemical) calorie is 4.184 joules — the energy to heat 1 g of water by 1 °C. |
| Kilocalorie (food Calorie) | kcal | A kilocalorie is 1,000 calories — the "Calorie" printed on food labels. |
| Kilowatt-hour | kWh | A kilowatt-hour is 3.6 million joules, the unit on electricity bills. |
| British thermal unit | BTU | A BTU (IT) is about 1,055 joules, used for heating and air-conditioning capacity. |
All energy conversions
J to kJ · J to cal · J to kcal · J to kWh · J to BTU · kJ to J · kJ to cal · kJ to kcal · kJ to kWh · kJ to BTU · cal to J · cal to kJ · cal to kcal · cal to kWh · cal to BTU · kcal to J · kcal to kJ · kcal to cal · kcal to kWh · kcal to BTU · kWh to J · kWh to kJ · kWh to cal · kWh to kcal · kWh to BTU · BTU to J · BTU to kJ · BTU to cal · BTU to kcal · BTU to kWh