Joules to calories
Type a value in joules to see it in calories straight away, or type in the second box to convert back.
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How to use it
- Type the value in the joules box.
- Read the result in calories as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
cal = J × 0.2390057361
Multiply the value in joules by 0.2390057361 to get calories.
Example
To convert 25 J to calories: 25 × 0.2390057361 = 5.97514 cal.
Conversion table
| Joules (J) | Calories (cal) |
|---|---|
| 1 | 0.239006 |
| 2 | 0.478011 |
| 3 | 0.717017 |
| 5 | 1.19503 |
| 10 | 2.39006 |
| 20 | 4.78011 |
| 25 | 5.97514 |
| 50 | 11.9503 |
| 100 | 23.9006 |
| 250 | 59.7514 |
| 500 | 119.503 |
| 1,000 | 239.006 |
About the units
- Joule
- The SI unit of energy, equal to the work done by a force of one newton moving an object one meter.
- Calorie
- The small calorie in its thermochemical definition, exactly 4.184 joules. The food calorie on labels equals 1000 of these.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many calories are in one joule?
1 J = 0.239006 cal exactly.
How do I convert joules to calories?
Use cal = J × 0.2390057361. For example, 25 J = 5.97514 cal.
How many joules are in one calorie?
1 cal = 4.184 J.
Which calorie do these converters use?
The thermochemical calorie, exactly 4.184 joules, the factor many countries use to turn kcal into kJ on food labels. The International Table calorie is 4.1868 joules, less than 0.07% larger.
What is the difference between kW and kWh?
A kilowatt is a unit of power, the rate of using energy, while a kilowatt-hour is an amount of energy. A 2 kW heater running for three hours uses 6 kWh.