How many joules are in one kilojoule?

There are 1,000 joules in 1 kilojoule.

How do you convert joules to kilojoules?

Multiply the number of joules by 0.001 — or use the formula kJ = J ÷ 1,000.

What is 6 joules in kilojoules?

6 joules is 0.006 kilojoules. 6 ÷ 1,000 = 0.006 kilojoules.

Is the joules to kilojoules conversion exact?

Yes. The relationship is fixed by definition, so 0.001 is an exact conversion factor — only the displayed result is rounded.

Joules to Kilojoules Converter

Convert joules to kilojoules instantly with this free joules to kilojoules converter. Enter any value to get an accurate energy conversion, plus the formula, the conversion factor and a full reference table.

What is 1 joule in kilojoules?

1 joule is equal to exactly 0.001 kilojoules.

1 ÷ 1,000 = 0.001 kilojoules

Amount

Result0.001

1 joule = 0.001 kilojoules

Joules to Kilojoules formula

kJ = J ÷ 1,000

The joules to kilojoules conversion factor is 0.001, which is exact by definition. 1 joule = 0.001 kilojoules, and 1 kilojoule = 1,000 joules.

Worked examples

2 joules = 0.002 kilojoules — 2 ÷ 1,000 = 0.002 kilojoules
6 joules = 0.006 kilojoules — 6 ÷ 1,000 = 0.006 kilojoules
10 joules = 0.01 kilojoules — 10 ÷ 1,000 = 0.01 kilojoules

Joules to Kilojoules conversion table

Every value below is calculated with the exact conversion factor and rounded for display.

joules to kilojoules conversion table
Joules (J)	Kilojoules (kJ)
1 J	0.001 kJ
2 J	0.002 kJ
3 J	0.003 kJ
4 J	0.004 kJ
5 J	0.005 kJ
6 J	0.006 kJ
7 J	0.007 kJ
8 J	0.008 kJ
9 J	0.009 kJ
10 J	0.01 kJ
12 J	0.012 kJ
15 J	0.015 kJ
20 J	0.02 kJ
25 J	0.025 kJ
30 J	0.03 kJ
50 J	0.05 kJ
75 J	0.075 kJ
100 J	0.1 kJ
500 J	0.5 kJ
1,000 J	1 kJ

When you need to convert joules to kilojoules

Comparing food energy labelled in calories with labels in kilojoules.
Reading utility bills and appliance ratings that mix kWh, joules and BTU.

Common mistakes to avoid

Dividing when you should multiply. Because 1 joule = 0.001 kilojoules, the answer should be smaller than the number you started with.
Rounding too early. Convert first at full precision, then round the final answer to the precision the task actually needs.

How precise does the answer need to be?

Round only at the end, and only to the precision your task actually needs. The converter above keeps full double precision internally and rounds for display.

How these units are defined

Joule (J): The SI unit of energy: one newton-meter. This unit's relationship to the SI base unit is exact by definition, so no rounding enters the conversion factor.
Kilojoule (kJ): 1,000 joules; food energy labelling in Australia and New Zealand. This unit's relationship to the SI base unit is exact by definition, so no rounding enters the conversion factor.

Frequently asked questions

What is 1 joule in kilojoules?: 1 joule is equal to 0.001 kilojoules.
How many joules are in one kilojoule?: There are 1,000 joules in 1 kilojoule.
How do you convert joules to kilojoules?: Multiply the number of joules by 0.001 — or use the formula kJ = J ÷ 1,000.
What is 6 joules in kilojoules?: 6 joules is 0.006 kilojoules. 6 ÷ 1,000 = 0.006 kilojoules.
Is the joules to kilojoules conversion exact?: Yes. The relationship is fixed by definition, so 0.001 is an exact conversion factor — only the displayed result is rounded.