Joules to Calories
The joule is the SI unit of energy, defined as the work done by one newton over one meter. A small calorie is the energy to raise 1 gram of water by 1°C, a base unit distinct from the food Calorie (kcal). 1 J equals ≈0.239006 cal, so converting between them is a matter of multiplying by that fixed factor — type any value into the converter below and both sides update instantly as you type.
Both units belong to energy, measured here against energy's base unit (J) — every other energy unit on this site converts through that same reference point, which is why the table below can also be read as a quick cross-check against nearby values.
Formula
cal = J × ≈0.239006
J = cal × 4.184
Worked example: 5 J × ≈0.239006 = ≈1.19503 cal.
Conversion table
| Joule (J) | Calorie (cal) |
|---|---|
| 1 J | ≈0.239006 cal |
| 2 J | ≈0.478011 cal |
| 3 J | ≈0.717017 cal |
| 5 J | ≈1.19503 cal |
| 10 J | ≈2.39006 cal |
| 20 J | ≈4.78011 cal |
| 25 J | ≈5.97514 cal |
| 50 J | ≈11.9503 cal |
| 100 J | ≈23.9006 cal |
| 250 J | ≈59.7514 cal |
| 500 J | ≈119.503 cal |
| 1,000 J | ≈239.006 cal |
Frequently asked
- How many Calories in a joule?
- 1 J equals ≈0.239006 cal.
- How do I convert Joules to Calories?
- Multiply the value in J by ≈0.239006 to get cal. The converter above does this instantly as you type.
- Is the conversion exact?
- Yes — Joule and Calorie are both defined by a fixed conversion factor to energy's base unit (J), so the result shown is exact to the precision displayed, not an approximation.