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1 calorie is approximately equal to 0.004184 kilojoules (kj).
This conversion is based on the fact that one calorie (cal), a unit of energy, equals 4.184 joules. Since a kilojoule (kj) is 1,000 joules, multiplying 4.184 by 1,000 gives the value for converting calories to kilojoules.
Table of Contents
Conversion Formula
The formula to convert calories to kilojoules is: kj = cal × 4.184. This works because each calorie contains 4.184 joules. To get kilojoules, you multiply the calorie amount by 4.184, as 1 kilojoule equals 1,000 joules. For example, converting 1 cal: 1 × 4.184 = 4.184 kj.
Conversion Tool
Result in kj:
Conversion Formula
The formula kj = cal × 4.184 works because one calorie contains exactly 4.184 joules. When converting to kilojoules, divide the joules by 1,000, or multiply calories by 4.184, to get the energy in kj. For example, 5 cal: 5 × 4.184 = 20.92 kj.
Conversion Example
- Convert 2 calories to kj:
- Multiply 2 by 4.184
- 2 × 4.184 = 8.368 kj
- Convert 10 calories to kj:
- 10 × 4.184 = 41.84 kj
- Convert 0.5 calories to kj:
- 0.5 × 4.184 = 2.092 kj
- Convert 100 calories to kj:
- 100 × 4.184 = 418.4 kj
- Convert 1.5 calories to kj:
- 1.5 × 4.184 = 6.276 kj
Conversion Chart
| Calories | Kilojoules (kj) |
|---|---|
| -24.0 | -100.416 |
| -20.0 | -83.68 |
| -16.0 | -66.944 |
| -12.0 | -50.208 |
| -8.0 | -33.472 |
| -4.0 | -16.736 |
| 0.0 | 0.0 |
| 4.0 | 16.736 |
| 8.0 | 33.472 |
| 12.0 | 50.208 |
| 16.0 | 66.944 |
| 20.0 | 83.68 |
| 24.0 | 100.416 |
| 26.0 | 108.184 |
Use this chart to quickly find the kilojoule equivalent for a range of calorie values, reading across the row from calories to kj.
Related Conversion Questions
- How many kilojoules equal 1 calorie in nutrition?
- What is the kj value for 1 calorie of energy?
- How do I convert 1 calorie to kilojoules manually?
- What is the energy difference between 1 calorie and 1 kj?
- Can I convert calories to kj using a calculator for 1 cal?
- Why is 1 cal equal to 4.184 kj?
- What is the precise kj equivalent for 1 calorie in food energy?
Conversion Definitions
Calorie
A calorie is a unit of energy originally used in physics and chemistry, defined as the amount of heat needed to raise the temperature of one gram of water by one degree Celsius at one atmosphere pressure. It is commonly used to measure food energy.
Kilojoule
A kilojoule (kj) is a metric unit of energy, equal to 1,000 joules. It is used to quantify energy transfer or consumption, especially in food nutrition and physical activities, providing a larger scale for measuring energy compared to joules.
Conversion FAQs
Why does 1 calorie equal 4.184 kilojoules?
This is because by definition, 1 cal equals 4.184 joules. Since a kilojoule is 1,000 joules, multiplying 4.184 by 1,000 gives the value for converting calories to kilojoules. This precise relationship is used in energy calculations across disciplines.
How accurate is the 4.184 conversion factor?
The 4.184 factor is an exact value based on the thermodynamic definition of the calorie. It is universally accepted in scientific and nutritional contexts, ensuring consistent conversions between calories and kilojoules for precise energy measurement.
Can I convert calories to kj with simple multiplication?
Yes, multiplying the number of calories by 4.184 provides the energy in kilojoules. This straightforward calculation is reliable because of the fixed relationship between the units, making quick conversions easy without complex formulas.
