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Convert joules to kilojoules (J to kJ)

Type a value in joules or in kilojoules: the other field updates as you type. Below you will find the formula, a worked example and a J to kJ chart.

Updated on

1 J = 0.001 kJ

How to convert joules to kilojoules

Formula: kJ = J × 0.001

Worked example: 1,000 J → 1,000 × 0.001 = 1 kJ

Joules to kilojoules conversion chart

Joules (J)Kilojoules (kJ)
1 J0.001 kJ
2 J0.002 kJ
3 J0.003 kJ
4 J0.004 kJ
5 J0.005 kJ
6 J0.006 kJ
7 J0.007 kJ
8 J0.008 kJ
9 J0.009 kJ
10 J0.01 kJ
12 J0.012 kJ
15 J0.015 kJ
20 J0.02 kJ
25 J0.025 kJ
30 J0.03 kJ
40 J0.04 kJ
50 J0.05 kJ
75 J0.075 kJ
100 J0.1 kJ
250 J0.25 kJ
500 J0.5 kJ
1,000 J1 kJ

What is a joule?

The joule is the SI unit of energy: the work done by a force of one newton over one meter, or one watt for one second. It is small; lifting an apple about one meter takes roughly one joule.

What is a kilojoule?

The kilojoule equals 1,000 joules. Food labels in Europe, Australia and New Zealand list energy in kJ next to kcal; a typical adult reference intake is 8,400 kJ, or 2,000 kcal, per day.

Frequently asked questions

How many kilojoules are in a joule?

A joule equals 0.001 kilojoules. To convert any value, multiply the number of joules by 0.001.

How do you convert joules to kilojoules?

Use the formula kJ = J × 0.001. Example: 1,000 J → 1,000 × 0.001 = 1 kJ.

How many joules are in a kilojoule?

A kilojoule equals 1,000 joules. That is the reverse conversion, from kilojoules to joules.

Results are rounded to 6 significant digits; the conversion factors are the exact legal definitions.