1 calorie is equal to approximately 0.004184 kilojoules.
This conversion is based on the fact that 1 calorie (small calorie) equals 4.184 joules, and since 1 kilojoule is 1000 joules, multiplying 4.184 by 1/1000 gives the value in kilojoules.
Conversion Result for 1 Calorie
Converting 1 calorie to kilojoules results in about 0.0042 kJ.
Conversion Tool
Result in kj:
Conversion Formula
The formula to convert calories to kilojoules is: kj = calories * 4.184. This works because each calorie equals 4.184 joules, and converting joules to kilojoules involves dividing by 1000. For example, 1 calorie times 4.184 gives 4.184 joules, which is 0.004184 kilojoules.
Conversion Example
- Convert 5 calories:
- Multiply 5 by 4.184: 5 * 4.184 = 20.92 joules
- Divide by 1000 to get kilojoules: 20.92 / 1000 = 0.02092 kj
- Convert 10 calories:
- 10 * 4.184 = 41.84 joules
- 41.84 / 1000 = 0.04184 kj
- Convert 0.5 calories:
- 0.5 * 4.184 = 2.092 joules
- 2.092 / 1000 = 0.002092 kj
- Convert 20 calories:
- 20 * 4.184 = 83.68 joules
- 83.68 / 1000 = 0.08368 kj
- Convert 2 calories:
- 2 * 4.184 = 8.368 joules
- 8.368 / 1000 = 0.008368 kj
Conversion Chart
The table below shows calorie values from -24.0 to 26.0 and their equivalent in kilojoules. To use it, find your calorie value in the first column, then read across to see the corresponding kJ value.
| Calories | Kilojoules (kJ) |
|---|---|
| -24.0 | -0.1002 |
| -23.0 | -0.0963 |
| -22.0 | -0.0920 |
| -21.0 | -0.0878 |
| -20.0 | -0.0837 |
| -19.0 | -0.0796 |
| -18.0 | -0.0754 |
| -17.0 | -0.0712 |
| -16.0 | -0.0670 |
| -15.0 | -0.0628 |
| -14.0 | -0.0586 |
| -13.0 | -0.0544 |
| -12.0 | -0.0502 |
| -11.0 | -0.0460 |
| -10.0 | -0.0418 |
| -9.0 | -0.0376 |
| -8.0 | -0.0335 |
| -7.0 | -0.0293 |
| -6.0 | -0.0251 |
| -5.0 | -0.0209 |
| -4.0 | -0.0167 |
| -3.0 | -0.0125 |
| -2.0 | -0.0084 |
| -1.0 | -0.0042 |
| 0.0 | 0.0000 |
| 1.0 | 0.0042 |
| 2.0 | 0.0084 |
| 3.0 | 0.0125 |
| 4.0 | 0.0167 |
| 5.0 | 0.0209 |
| 6.0 | 0.0251 |
| 7.0 | 0.0293 |
| 8.0 | 0.0335 |
| 9.0 | 0.0376 |
| 10.0 | 0.0418 |
| 11.0 | 0.0460 |
| 12.0 | 0.0502 |
| 13.0 | 0.0544 |
| 14.0 | 0.0586 |
| 15.0 | 0.0628 |
| 16.0 | 0.0670 |
| 17.0 | 0.0712 |
| 18.0 | 0.0754 |
| 19.0 | 0.0796 |
| 20.0 | 0.0837 |
| 21.0 | 0.0878 |
| 22.0 | 0.0920 |
| 23.0 | 0.0963 |
| 24.0 | 0.1002 |
| 25.0 | 0.1046 |
| 26.0 | 0.1088 |
Related Conversion Questions
- How many kilojoules are in 1 calorie of energy?
- What is the kj equivalent of 1 calorie in food energy?
- How do I convert calories to kilojoules for nutritional labels?
- What is the formula to change calorie measurements into kj?
- Can I convert 1 calorie to kj using a calculator online?
- What is the energy in kj for 1 small calorie?
- How many kilojoules does 1 calorie represent in exercise energy?
Conversion Definitions
A calorie is a unit of energy that measures the amount of heat needed to raise the temperature of one gram of water by one degree Celsius. It is primarily used in nutrition to quantify food energy.
Kilojoule (kJ) is a metric unit of energy equal to 1,000 joules, used for measuring energy in scientific, nutritional, and physical contexts. It is a standard SI unit for energy measurements.
Conversion FAQs
Why is the calorie used in nutrition instead of the joule?
Calories are historically rooted in food energy measurement because they relate directly to the heat energy released during metabolic processes. They are more familiar in dietary contexts, despite joules being the SI unit.
Can I convert calories to kilojoules manually without a calculator?
Yes, by multiplying the number of calories by 4.184, you can manually convert calories into kilojoules. For example, 10 calories times 4.184 equals 41.84 kj, which is straightforward with basic multiplication.
Is the conversion between calories and kj exact or approximate?
The conversion is precise for the small calorie definition, with 1 calorie exactly equal to 4.184 joules. However, in nutritional contexts, the calorie is often rounded, making the conversion an approximation in some cases.
How does energy measurement differ between food energy and scientific applications?
Food energy uses calories (or kilocalories), while scientific applications typically use joules or kilojoules. The conversion factor bridges the two, but differences in definitions can lead to slight variations in measurements.