1 calorie equals approximately 0.0042 kilojoules.
The conversion from calorie to kilojoules is based on the fact that 1 calorie (cal) is equal to 4.184 joules (J). Since kilojoules (kJ) are 1,000 joules, dividing 4.184 by 1,000 gives the conversion factor. Therefore, multiplying calories by 0.004184 results in the energy in kilojoules.
Conversion Result
1 calorie is approximately 0.0042 kj.
Conversion Tool
Result in kj:
Conversion Formula
The formula to convert calories to kilojoules involves multiplying the number of calories by 4.184, which is the number of joules in one calorie. Since 1 kilojoule equals 1,000 joules, dividing 4.184 by 1,000 gives 0.004184. For example, 10 calories multiply by 0.004184 equals 0.04184 kj.
Conversion Example
- Convert 5 calories:
- Multiply 5 by 0.004184
- 5 * 0.004184 = 0.02092
- Result: 5 calories equals 0.02092 kj
- Convert 10 calories:
- Multiply 10 by 0.004184
- 10 * 0.004184 = 0.04184
- Result: 10 calories equals 0.04184 kj
- Convert 20 calories:
- Multiply 20 by 0.004184
- 20 * 0.004184 = 0.08368
- Result: 20 calories equals 0.08368 kj
Conversion Chart
This chart shows how different calorie values convert to kilojoules. Read the table by looking at the calorie value in the first column and noting its equivalent in the second column.
| Calories | Kilojoules (kj) |
|---|---|
| -24.0 | -0.1003 |
| -20.0 | -0.0837 |
| -15.0 | -0.0628 |
| -10.0 | -0.0418 |
| -5.0 | -0.0209 |
| 0.0 | 0.0 |
| 5.0 | 0.02092 |
| 10.0 | 0.04184 |
| 15.0 | 0.06276 |
| 20.0 | 0.08368 |
| 25.0 | 0.1046 |
| 26.0 | 0.1088 |
To use the chart, find your calorie value in the first column and see the corresponding kilojoule value in the second.
Related Conversion Questions
- How many kj are in 1 calorie of energy?
- What is the kj equivalent of 1 calorie?
- Convert 1 calorie to kilojoules for food energy measurement?
- How do I convert calories to kj for nutrition facts?
- What is the energy in kj of 1 calorie burned during exercise?
- Is 1 calorie equal to 0.0042 kj or different?
- How many kj does 2 calories amount to?
Conversion Definitions
Calorie
A calorie is a unit of energy, historically used to measure food energy. It represents the amount of heat needed to raise the temperature of one gram of water by one degree Celsius. The small calorie (cal) is different from the large calorie (kcal), which is used in nutrition.
Kilojoule
A kilojoule (kJ) is a metric unit of energy equal to 1,000 joules. It is used worldwide for scientific and nutritional energy measurements. It quantifies the work done or heat transferred and is part of the International System of Units (SI).
Conversion FAQs
Why is the conversion factor from calorie to kj 0.004184?
This factor comes from the fact that 1 calorie equals exactly 4.184 joules. Dividing 4.184 joules by 1,000 gives 0.004184 kilojoules, which is used to convert calories into kilojoules. This precise value ensures accurate energy calculations.
Can I convert calories to kilojoules manually using this formula?
Yes, by multiplying the number of calories by 0.004184, you can find the equivalent energy in kilojoules. For example, 7 calories times 0.004184 equals approximately 0.029288 kj. This method provides quick manual conversions without requiring a calculator.
Is there a difference between calories used in food and scientific calories?
Yes, the calorie in nutrition (kcal) is actually a kilocalorie, equal to 1,000 small calories (cal). The scientific calorie (cal) is less common now, replaced by the joule and kilojoule, but both measure energy. They are related through the conversion factor of 4.184 joules per calorie.
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