A kilocalorie (kcal) equals 1,000 small calories and is the unit behind the food "Calorie" shown on nutrition labels.
Kilocalories to Kilojoules
Convert Kilocalorie (kcal) to Kilojoule (kJ) instantly with an exact formula, conversion table, and FAQ.
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Convert kilocalories (kcal) to kilojoules (kJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
kJ = kcal × 4.184
Results update instantly for Kilocalories to Kilojoules conversions.
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Formula
kJ = kcal × 4.184
kcal = kJ × 0.2390057361
Conversion table
| 1 kcal | 4.184 kJ |
| 5 kcal | 20.92 kJ |
| 10 kcal | 41.84 kJ |
| 20 kcal | 83.68 kJ |
| 50 kcal | 209.2 kJ |
| 100 kcal | 418.4 kJ |
| 500 kcal | 2092 kJ |
| 1000 kcal | 4184 kJ |
Related conversions
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How the formula works
Both kilocalorie and kilojoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in kilocalories by 4.184 to get kilojoules. To reverse the conversion, multiply a kilojoule value by 0.2390057361 to get back to kilocalories.
Frequently asked questions
What is Kilocalorie (kcal)?
A kilocalorie (kcal) equals 1,000 small calories and is the unit behind the food "Calorie" shown on nutrition labels.
What is Kilojoule (kJ)?
A kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
How do I convert kilocalories to kilojoules?
Multiply the kilocalorie value by 4.184 to get the equivalent in kilojoules. For example, 5 kcal × 4.184 = 20.92 kJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 4.184 is an exact, non-rounded value.
Can I convert kilojoules back to kilocalories?
Yes. Divide the kilojoule value by 4.184, or multiply it by 0.2390057361, to get kilocalories.
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About converting kilocalories to kilojoules
A kilocalorie (kcal) equals 1,000 small calories and is the unit behind the food "Calorie" shown on nutrition labels. A kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
Use this calculator to move between kilocalories and kilojoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.