1 calorie equals approximately 0.004184 kilojoules.
This conversion is based on the fact that one small calorie, used in nutrition, is defined as the amount of energy needed to raise the temperature of one gram of water by one degree Celsius. To convert calories to kilojoules, the value is multiplied by 0.004184, because 1 calorie = 4.184 joules, and 1 kilojoule = 1000 joules.
Conversion Result for 1 calorie
1 calorie is approximately 0.0042 kj when rounded to four decimal places. This means that the energy contained within a single calorie is a tiny fraction of a kilojoule.
Conversion Tool
Result in kj:
Conversion Formula
The formula to convert calories to kilojoules multiplies the number of calories by 0.004184, because one calorie equals 4.184 joules, and there are 1000 joules in a kilojoule. For example, converting 1 calorie:
- 1 calorie x 4.184 joules = 4.184 joules
- 4.184 joules / 1000 = 0.004184 kj
This calculation ensures an accurate conversion from calories to kilojoules, making it easy to switch between energy units.
Conversion Example
- Convert 2 calories:
- 2 x 4.184 = 8.368 joules
- 8.368 / 1000 = 0.008368 kj
- Convert 5 calories:
- 5 x 4.184 = 20.92 joules
- 20.92 / 1000 = 0.02092 kj
- Convert 10 calories:
- 10 x 4.184 = 41.84 joules
- 41.84 / 1000 = 0.04184 kj
- Convert 0.5 calories:
- 0.5 x 4.184 = 2.092 joules
- 2.092 / 1000 = 0.002092 kj
Conversion Chart
| Calories | kJ |
|---|---|
| -24.0 | -0.1002 |
| -20.0 | -0.0837 |
| -15.0 | -0.0628 |
| -10.0 | -0.0418 |
| -5.0 | -0.0209 |
| 0.0 | 0.0 |
| 1.0 | 0.0042 |
| 5.0 | 0.0209 |
| 10.0 | 0.0418 |
| 15.0 | 0.0628 |
| 20.0 | 0.0837 |
| 24.0 | 0.1002 |
| 26.0 | 0.1086 |
This chart helps you see how different calorie values convert into kilojoules, from negative to positive values, showing the energy change in each case.
Related Conversion Questions
- How many kilojoules are in 1 calorie of food energy?
- What is the kj equivalent of burning 1 calorie during exercise?
- How do I convert calories to kilojoules for nutrition labels?
- What is the energy difference between 1 calorie and 1 kj?
- Can I convert small calorie measurements to kilojoules accurately?
- How many kj are in a dietary calorie?
- What is the kilojoule value for 1 calorie in scientific experiments?
Conversion Definitions
Calorie
A calorie is a unit measuring energy, specifically the amount needed to raise the temperature of one gram of water by one degree Celsius. In nutrition, it represents the energy foods provide, with 1 calorie equaling approximately 4.184 joules.
kJ (Kilojoule)
A kilojoule is a metric unit of energy equal to 1000 joules. It is used frequently in scientific contexts to express energy amounts, including food energy and physical work, making it easier to compare large energy quantities.
Conversion FAQs
Why is the calorie in nutrition different from the scientific calorie?
The nutritional calorie (also called a kilocalorie) equals 1000 scientific calories, meaning that 1 nutritional calorie is actually 1000 of the small calories used in physics. This difference is important for accurate energy calculations in food.
How accurate is the conversion from calories to kilojoules?
The conversion factor of 4.184 joules per calorie is precise for small calories, making the calculation highly reliable. Small variations might occur in specific contexts, but generally, this value is accepted internationally.
Can I convert calories to other energy units using this method?
Yes, by knowing the equivalent in joules, you can convert calories to other units like calories (small or large), foot-pounds, or British thermal units (BTU) with appropriate conversion factors, but the basic calorie-to-kilojoule calculation remains the same.
