The conversion of 1 calorie to kilojoules results in approximately 4.184 kJ. This shows how energy measurements in calories translate into the metric system’s energy units, providing a clearer perspective on energy content in food and other sources.
One calorie, often used to describe food energy, equals exactly 4.184 kilojoules. The conversion is based on the physical relationship where 1 calorie (small calorie) is defined as the amount of heat needed to raise the temperature of 1 gram of water by 1 degree Celsius at 1 atmosphere of pressure. Therefore, multiplying calories by 4.184 converts to kilojoules, which are a larger unit of energy measurement used internationally and in scientific contexts.
Conversion Tool
Result in kj:
Conversion Formula
The conversion from calories to kilojoules uses the formula: kj = calories × 4.184. This formula works because 1 calorie equals 4.184 kilojoules, based on the energy needed to raise water’s temperature. For example, converting 2 calories: 2 × 4.184 = 8.368 kJ. The multiplication scales the energy from smaller calories to the larger kilojoules, making it easier to compare energy content across different measurement systems.
Conversion Example
- Convert 3 calories:
- Multiply 3 by 4.184.
- 3 × 4.184 = 12.552 kJ.
- So, 3 calories equals 12.552 kilojoules.
- Convert 0.5 calories:
- Multiply 0.5 by 4.184.
- 0.5 × 4.184 = 2.092 kJ.
- Thus, 0.5 calories equals 2.092 kilojoules.
- Convert 10 calories:
- Multiply 10 by 4.184.
- 10 × 4.184 = 41.84 kJ.
- Therefore, 10 calories are 41.84 kilojoules.
- Convert 1.5 calories:
- Multiply 1.5 by 4.184.
- 1.5 × 4.184 = 6.276 kJ.
- Hence, 1.5 calories equal 6.276 kilojoules.
Conversion Chart
This chart displays values from -24.0 to 26.0 in calories and their equivalent in kilojoules, based on the conversion factor 4.184. To read it, find the calorie value in the first column, then look across to see the corresponding kilojoule value. It helps quickly determine energy conversions for various inputs.
| Calories | Kilojoules (kJ) |
|---|---|
| -24.0 | -100.416 |
| -23.0 | -96.232 |
| -22.0 | -92.048 |
| -21.0 | -87.864 |
| -20.0 | -83.68 |
| -19.0 | -79.496 |
| -18.0 | -75.312 |
| -17.0 | -71.128 |
| -16.0 | -66.944 |
| -15.0 | -62.76 |
| -14.0 | -58.576 |
| -13.0 | -54.392 |
| -12.0 | -50.208 |
| -11.0 | -46.024 |
| -10.0 | -41.84 |
| -9.0 | -37.656 |
| -8.0 | -33.472 |
| -7.0 | -29.288 |
| -6.0 | -25.104 |
| -5.0 | -20.92 |
| -4.0 | -16.736 |
| -3.0 | -12.552 |
| -2.0 | -8.368 |
| -1.0 | -4.184 |
| 0.0 | 0.0 |
| 1.0 | 4.184 |
| 2.0 | 8.368 |
| 3.0 | 12.552 |
| 4.0 | 16.736 |
| 5.0 | 20.92 |
| 6.0 | 25.104 |
| 7.0 | 29.288 |
| 8.0 | 33.472 |
| 9.0 | 37.656 |
| 10.0 | 41.84 |
| 11.0 | 46.024 |
| 12.0 | 50.208 |
| 13.0 | 54.392 |
| 14.0 | 58.576 |
| 15.0 | 62.76 |
| 16.0 | 66.944 |
| 17.0 | 71.128 |
| 18.0 | 75.312 |
| 19.0 | 79.496 |
| 20.0 | 83.68 |
| 21.0 | 87.864 |
| 22.0 | 92.048 |
| 23.0 | 96.232 |
| 24.0 | 100.416 |
| 25.0 | 104.6 |
| 26.0 | 108.784 |
Related Conversion Questions
- How many kilojoules are in 1 calorie of energy?
- What is the kilojoule equivalent of 1 food calorie?
- Convert 1 small calorie to kilojoules?
- How do I change calories to kilojoules for nutritional info?
- What is the energy in kilojoules for 1 calorie burned during exercise?
- How many kilojoules are in a single calorie of heat?
- Is 1 calorie equal to 4.184 kilojoules or more?
Conversion Definitions
A calorie (cal) is a unit of energy measuring heat, representing the amount needed to raise 1 gram of water by 1°C. Kilojoules (kJ) are metric energy units equal to 1,000 joules, used globally for scientific, nutritional, and physical energy measurements. They provide a standard metric measure for energy transfer.
Conversion FAQs
Can I convert calories to kilojoules without a calculator?
Yes, you can estimate by multiplying calories by roughly 4.2, but for precise calculations, using a calculator or the conversion factor 4.184 is recommended. Rounding may lead to slight inaccuracies, especially in scientific contexts.
Why is the calorie converted to kilojoules so often in nutrition?
Because kilojoules are part of the metric system, they provide a universal standard for energy measurement. Countries outside the United States prefer kilojoules for labeling food energy because they align with the SI system and are easier to standardize across scientific disciplines.
What is the difference between a small calorie and a large calorie?
The small calorie (cal) measures heat needed to raise 1 gram of water by 1°C, while the large calorie (kcal) or food calorie equals 1,000 small calories. Food labels use kilocalories, often just called calories, which can be confusing without clarification.