Energy Converter
Convert between energy units — joules, calories, kilowatt-hours and BTU.
Result updates as you type
Recent:
1 Joule = 0.23900574 Calorie
Popular energy conversions
Common energy conversions
Supported energy units
| Unit | Symbol | Reference |
|---|---|---|
| Joule | J | Base unit for energy conversions. |
| Calorie | cal | 1 Calorie = 4.184 Joules. |
| Kilowatt-hour | kWh | 1 Kilowatt-hour = 3600000 Joules. |
| BTU | BTU | 1 BTU = 1055.06 Joules. |
4 units supported · instant, precise results
How energy conversion works
Each energy conversion is performed by first expressing the input in a single base unit (Joules) and then scaling to the target unit. Factors are stored to full precision, so a value converted to another unit and back returns the original number. Results here match the formula, worked examples and reference table shown on every individual conversion page.
Frequently asked questions
- What energy units can I convert?
- This energy converter supports Joules, Calories, Kilowatt-hours and BTU. Select any two units to convert between them instantly.
- Are the energy conversions accurate?
- Yes. Every conversion uses standard, internationally recognised factors and is calculated to full precision, then rounded only for display.
- Can I use this energy converter on mobile?
- Yes. The converter works in any modern browser on phones, tablets and desktops, with no installation required.