Convert Calorie to Kilojoule
Use this free converter to change calories (cal) into kilojoules (kJ). Calorie and kilojoule both measure energy. As a quick reference, 1 cal equals 0.004184 kJ, and 1 kJ equals 239.00574 cal.
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Kilojoule (kJ)
0.004184
1 cal = 0.004184 kJ
Energy conversion table
| Calorie | Kilojoule |
|---|---|
| 0.01 | 0.00004184 |
| 0.1 | 0.0004184 |
| 0.5 | 0.002092 |
| 1 | 0.004184 |
| 2 | 0.008368 |
| 3 | 0.012552 |
| 5 | 0.02092 |
| 10 | 0.04184 |
| 20 | 0.08368 |
| 25 | 0.1046 |
| 50 | 0.2092 |
| 100 | 0.4184 |
| 1,000 | 4.184 |
How to convert Calorie to Kilojoule
Multiply the calorie value by 0.004184 to get kilojoules.
- Enter the number of calories you want to convert.
- The converter instantly shows the equivalent value in kilojoules.
- Worked example: 15 cal × 0.004184 = 0.06276 kJ.
- Use the swap button to reverse the conversion (kilojoule to calorie).
About these units
Calorie (cal)
- Definition
- A calorie (cal) is the energy needed to raise one gram of water by one degree Celsius, about 4.184 joules.
- History
- Defined in the 19th century, the small calorie was later joined by the larger food Calorie.
- Current use
- Calories appear in chemistry and, as kilocalories, in nutrition.
Kilojoule (kJ)
- Definition
- A kilojoule (kJ) is 1,000 joules, a practical size for food energy and mechanical work.
- History
- It is a metric multiple of the joule.
- Current use
- Kilojoules express food energy on nutrition labels in many countries.
Frequently asked questions
How many kilojoules are in a calorie?
There are 0.004184 kJ in 1 cal. To convert, multiply the number of calories by 0.004184.
How do I convert calories to kilojoules?
Multiply the calorie value by 0.004184 to get kilojoules. For example, 10 cal = 0.04184 kJ.
Is this calorie-to-kilojoule converter free?
Yes. This converter is completely free, runs entirely in your browser, and requires no sign-up. Your inputs never leave your device.
Convert Calorie to other energy units
| Unit | 1 Calorie equals |
|---|---|
| Joule (J) | 4.184 J |
| Kilojoule (kJ) | 0.004184 kJ |
| Kilocalorie (kcal) | 0.001 kcal |
| Watt Hour (Wh) | 0.0011622222 Wh |
| Kilowatt Hour (kWh) | 0.0000011622222 kWh |
| Electronvolt (eV) | 2.6114e+19 eV |
| British Thermal Unit (BTU) | 0.0039656668 BTU |
| Foot-Pound (ft·lb) | 3.08596 ft·lb |