Calories to Joules converter
Convert calories (cal) to joules (J) — results update instantly as you type.
Calories to Joules
To
1 cal = 4.184 J
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How to convert Calories to Joules
Energy appears as joules in physics, calories in nutrition, and kilowatt hours on electricity bills. All measure the same thing — the capacity to do work — just at very different scales.
Everything converts through the joule. One (small) calorie is exactly 4.184 joules, a food Calorie (kcal) is 4,184 joules, and one kilowatt hour is exactly 3.6 million joules.
Formula
cal × 4.184 = J
Multiply your calories value by 4.184 to get joules. For the reverse, divide by the same factor.
Calories to Joules conversion table
| Calories | Joules |
|---|---|
| 1 cal | 4.184 J |
| 2 cal | 8.368 J |
| 5 cal | 20.92 J |
| 10 cal | 41.84 J |
| 25 cal | 104.6 J |
| 100 cal | 418.4 J |
Common use cases
- Comparing food energy (kcal) with exercise burn
- Understanding electricity bills in kWh
- Physics and engineering calculations in joules
- Battery capacity comparisons in watt hours
Frequently asked questions
A food Calorie (capital C) is actually a kilocalorie — 1,000 small calories. Nutrition labels always mean kilocalories.