Joules to Kilojoules Converter

Joules to Kilojoules Converter

Kilojoules
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Calories (kcal)
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1 kJ = 1000 J · 1 kcal = 4.184 kJ

How to convert joules to kilojoules

To convert joules to kilojoules, divide by 1000. There are exactly 1000 joules in every kilojoule. For example, 5000 J ÷ 1000 = 5 kJ. Going the other way, multiply kilojoules by 1000 to get joules.

To convert joules to kilocalories (food Calories), divide by 4184. So 4184 J ÷ 4184 = 1 kcal.

1 kJ = 1000 J = 0.239006 kcal. Kilojoules are commonly used in food labeling in Australia and Europe as an alternative to Calories. 1 food Calorie = 1 kcal = 4.184 kJ.

Joules to kilojoules conversion table

Joules (J) Kilojoules (kJ) Kilocalories (kcal)
100 J0.1 kJ0.0239 kcal
500 J0.5 kJ0.1195 kcal
1000 J1 kJ0.239 kcal
4184 J4.184 kJ1 kcal
10,000 J10 kJ2.390 kcal
100,000 J100 kJ23.901 kcal
8,368,000 J8368 kJ2000 kcal

Frequently asked questions

How many joules are in a kilojoule?
There are exactly 1000 joules in 1 kilojoule. The prefix “kilo” always means one thousand.
How many kJ is 1 Calorie (kcal)?
1 food Calorie (kcal) = 4.184 kJ = 4184 J. Food labels in Australia and Europe show kilojoules instead of Calories.
How many kJ is 2000 Calories?
2000 kcal = 8368 kJ. This is the average daily calorie intake for an adult.
How many joules is 5 kJ?
5 kJ = 5000 joules. Calculation: 5 × 1000 = 5000 J.
How many kcal is 100 kJ?
100 kJ = 23.901 kcal. Calculation: 100 ÷ 4.184 = 23.901 kcal.