Built for accuracy
History & favorites stay local
Energy units appear in fitness trackers, electrical billing, and industrial heating. This guide keeps the relationships clear so you can reconcile reports in any system.
Because energy spans mechanical work and heat, legacy and modern units coexist. Use the table to relate them all back to the joule, then cross-check the most common conversions for your domain.
This converter is focused on energy conversion guide only. Pick any units in this category and get results immediately.
Jump directly to any available converter for energy conversion guide units.
Every unit below references the SI base value so you can compare readings quickly.
| Unit | Symbol | 1 unit in J | Notes |
|---|---|---|---|
| Joule | J | Reference unit | — |
| Calorie | cal | 1 cal = 4.184 J | — |
| Kilojoule | kJ | 1 kJ = 1K J | — |
| British Thermal Unit | BTU | 1 BTU = 1.06K J | — |
| Kilocalorie (food) | kcal | 1 kcal = 4.18K J | — |
| Kilowatt Hour | kWh | 1 kWh = 3.6000×10^+6 J | — |
These presets mirror the quick actions available inside the SwapUnits converter.
A nutrition “Calorie” is a kilocalorie—the energy needed to raise 1 kilogram of water by 1 °C. Scientists often write kcal, while consumer packaging simplifies it to Calorie.
One kilowatt-hour equals roughly 3,412 BTU. HVAC designers use this conversion when comparing electric and gas heating efficiency.
Yes. One joule equals the work done by one newton of force acting through one meter. It is the SI unit for energy.
Head back to the SwapUnits converter to crunch numbers instantly and save your favorite presets.