A (small) calorie is a thermochemical unit of heat energy equal to 4.184 joules, historically the energy needed to raise 1 gram of water by 1°C.
Calories to Joules
Convert Calorie (cal) to Joule (J) instantly with an exact formula, conversion table, and FAQ.
Reserved for a responsive leaderboard above the conversion details.
Professional calculator style
World-scale conversion engine
30+ categories
6,500+ units
Instant results
Offline ready
Energy calculator
Energy Converter
Convert calories (cal) to joules (J) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
The joule (J) is the SI derived unit of energy, equal to the work done when a force of one newton acts over one meter.
J = cal × 4.184
Results update instantly for Calories to Joules conversions.
Reserved above the conversion cards and below the converter.
Formula
J = cal × 4.184
cal = J × 0.2390057361
Conversion table
| 1 cal | 4.184 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 |
| 500 cal | 2092 J |
| 1000 cal | 4184 J |
Related conversions
Reserved between the cards and the FAQ so the page stays balanced.
How the formula works
Both calorie and joule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in calories by 4.184 to get joules. To reverse the conversion, multiply a joule value by 0.2390057361 to get back to calories.
Frequently asked questions
What is Calorie (cal)?
A (small) calorie is a thermochemical unit of heat energy equal to 4.184 joules, historically the energy needed to raise 1 gram of water by 1°C.
What is Joule (J)?
The joule (J) is the SI derived unit of energy, equal to the work done when a force of one newton acts over one meter.
How do I convert calories to joules?
Multiply the calorie value by 4.184 to get the equivalent in joules. For example, 5 cal × 4.184 = 20.92 J.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 4.184 is an exact, non-rounded value.
Can I convert joules back to calories?
Yes. Divide the joule value by 4.184, or multiply it by 0.2390057361, to get calories.
Reserved between the FAQ and the article so the page stays balanced.
About converting calories to joules
A (small) calorie is a thermochemical unit of heat energy equal to 4.184 joules, historically the energy needed to raise 1 gram of water by 1°C. The joule (J) is the SI derived unit of energy, equal to the work done when a force of one newton acts over one meter.
Use this calculator to move between calories and joules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.