How to convert kilojoules to kilocalories
To convert a measurement in kilojoules to kilocalories, multiply the value by 0.239005736138. The conversion factor comes from the relationship between both units and the joule.
For example, to convert 5 kJ to kilocalories: 5 × 0.239005736138 = 1.195029 kcal.
What is a kilojoule?
A kilojoule equals 1,000 joules and is the standard metric unit for expressing food energy on nutrition labels in most of the world. As metric countries adopted SI units for food labeling, the kilojoule replaced the food calorie on packaging in regions such as Australia, New Zealand, and the European Union (shown alongside kcal).
Common uses of kilojoules include: Food energy on nutrition labels; Dietary and exercise energy tracking; Chemical reaction energy (enthalpy); Battery and mechanical energy specs.
What is a kilocalorie?
A kilocalorie equals 1,000 small calories, or exactly 4,184 joules, and is the 'Calorie' shown on food nutrition labels. The food Calorie (capital C) is actually a kilocalorie. This convention, established in nutrition science, means a 500-Calorie meal contains 500 kilocalories, or about 2,092 kilojoules.
Common uses of kilocalories include: Food energy (the dietary 'Calorie'); Metabolism and exercise burn estimates; Nutrition and diet planning; Bomb-calorimetry food testing.
Kilojoules to kilocalories worked examples
Here are some common values converted:
1 kJ = 0.239005736138 kcal 5 kJ = 1.195029 kcal 10 kJ = 2.390057 kcal 50 kJ = 11.950287 kcal 100 kJ = 23.900574 kcal
Frequently asked questions
How many kilocalories are in one kilojoule?
One kilojoule (kJ) equals 0.239005736138 kilocalories (kcal). Multiply any value in kilojoules by 0.239005736138 to convert to kilocalories.
How do I convert kilojoules to kilocalories?
Multiply the value in kilojoules by 0.239005736138. For example, 5 kJ × 0.239005736138 = 1.195029 kcal.
How do I convert kilocalories to kilojoules?
Multiply the value in kilocalories by 4.184, or divide by 0.239005736138. Use the swap button on the converter above to reverse the direction.
Is the kilojoule to kilocalorie conversion exact?
The thermochemical calorie is defined as exactly 4.184 J and the BTU as 1055.056 J. Conversions between SI energy units are exact.
What is the formula for kilojoules to kilocalories?
The formula is: kcal = kJ × 0.239005736138. This comes from the definition of both units relative to the joule.