Calories to Kilojoules Converter
Convert calories (cal) to kilojoules (kJ)
Result
0.004184 kJ
Kilojoules
1 cal = 0.004184 kJ
1 cal in other units
- 1Enter a valueType the number to convert
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- 3Read the resultSee it in every other unit too
How to convert calories to kilojoules
One calorie equals 0.004184 kilojoules, so multiply the number of calories by 0.004184.
kJ = cal × 0.004184
1 cal = 0.004184 kJ · 1 kJ = 239.0057 cal
Worked example
To convert 5 calories to kilojoules: 5 cal × 0.004184 = 0.02092 kJ.
About calories (cal)
A (small) calorie is 4.184 J, the energy to warm 1 g of water by 1 °C. Food “Calories” are actually kilocalories.
About kilojoules (kJ)
A kilojoule is 1,000 J. Food labels in many countries show energy in kJ alongside kcal.
More conversions
Calories to other units
Frequently asked questions
How many kilojoules are in one calorie?
One calorie equals 0.004184 kilojoules.
How many calories are in one kilojoule?
One kilojoule equals 239.0057 calories.
How do I convert calories to kilojoules?
Use the formula kJ = cal × 0.004184. For example, 5 cal × 0.004184 = 0.02092 kJ.