Calories to Joules Converter
Convert calorie to joule instantly. Type a value below — the result updates as you type.
When you need to convert calorie to joule
Energy conversions appear on nutrition labels, utility bills and appliance specs, letting you compare food energy, electricity use and heating output on a common scale.
Typical values: 0.5 cal is about 2.092 J, and 100 cal works out to roughly 418.4 J. Because the ratio is fixed at 4.184, you can scale any amount linearly — doubling the calories doubles the joules.
Food packaging, power meters and heating equipment each prefer different energy units, so converting makes them directly comparable.
How to convert calorie to joule
One calorie equals 4.184 joules. To convert, multiply the number of calories by 4.184:
joules = calories × 4.184
For example, 10 calories × 4.184 = 41.84 joules.
Calories to joules conversion table
| Energy (cal) | Joules (J) |
|---|---|
| 1 cal | 4.184 J |
| 2 cal | 8.368 J |
| 3 cal | 12.552 J |
| 5 cal | 20.92 J |
| 10 cal | 41.84 J |
| 20 cal | 83.68 J |
| 50 cal | 209.2 J |
| 100 cal | 418.4 J |
FAQ
How many joules are in a calorie?
One calorie = 4.184 joules.
How do I convert joules back to calories?
Divide by 4.184, or use the joules to calories converter.