Calorie converter (kcal ↔ kJ)
Switch from kilocalories to kilojoules in an instant: the two energy units shown on food labels. Free and instant.
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418
kilojoules (kJ)
Formula1 kcal = 4.184 kJ
European nutrition labels show energy in kJ and kcal. The « large calorie » (Cal) is equivalent to 1 kcal.
kcal and kJ: what is the difference?
The kilocalorie (kcal) and the kilojoule (kJ) measure the same thing, energy, but in two different units. The kilojoule is the official SI unit, while the kilocalorie is the traditional unit still most used in everyday life. The conversion is fixed: 1 kcal = 4.184 kJ, so 1 kJ ≈ 0.239 kcal.
Why both on packaging?
Regulations require the energy value to be shown in both units. When you read « 2,000 kcal / 8,400 kJ » on a pack, it is the same requirement expressed twice. To estimate your intake in practice, use our calorie table.
Frequently asked questions
How many kJ are in 100 kcal?
100 kcal is equivalent to 418.4 kJ. Conversely, 100 kJ is about 23.9 kcal.
Are a calorie and a kilocalorie the same thing?
In everyday language and in nutrition, yes: what we call a « calorie » is in fact a kilocalorie (kcal), or 1,000 « small » calories. Labels always use kcal.
Which unit should I look at on a label?
The two are equivalent: choose the one that means most to you. Most people compare their intake with their needs in kcal.
This tool provides an estimate for information only and does not replace the advice of a healthcare professional. No data you enter is collected or stored.