joules to kJ converter

1 joule equals 0.001 kilojoules. Conversions use kJ = J × 0.001

J → 0.001 kJ

kJ = J × 0.001

Converter

Worked examples

1 J = 0.001 kJ
2 J = 0.002 kJ
5 J = 0.005 kJ
10 J = 0.01 kJ
100 J = 0.1 kJ

joules to kilojoules conversion table

J	kJ	Arithmetic
1 J	0.001 kJ	× 0.001
2 J	0.002 kJ	× 0.001
3 J	0.003 kJ	× 0.001
4 J	0.004 kJ	× 0.001
5 J	0.005 kJ	× 0.001
6 J	0.006 kJ	× 0.001
8 J	0.008 kJ	× 0.001
10 J	0.01 kJ	× 0.001
12 J	0.012 kJ	× 0.001
15 J	0.015 kJ	× 0.001
20 J	0.02 kJ	× 0.001
25 J	0.025 kJ	× 0.001
30 J	0.03 kJ	× 0.001
40 J	0.04 kJ	× 0.001
50 J	0.05 kJ	× 0.001
60 J	0.06 kJ	× 0.001
70 J	0.07 kJ	× 0.001
80 J	0.08 kJ	× 0.001
90 J	0.09 kJ	× 0.001
100 J	0.1 kJ	× 0.001

How to convert J to kJ

Take your value in joules.
Multiply by 0.001
That is your answer in kilojoules — no rounding needed until you choose a display precision.

Related conversions

kJ to J J to cal J to kcal J to Wh J to kWh J to Btu kJ to cal kJ to kcal kJ to Wh all energy units

Questions

How many kilojoules in 1 joule?

Exactly 0.001 kJ. The factor follows from the definitions of both units, not from a measurement, so it is exact.

How do I convert J to kJ?

Multiply the joules figure by 0.001 — or use the converter above, which updates as you type.

Is J to kJ the same as kJ to J?

No — they are inverses. One J is 0.001 kJ, while one kJ is 1,000 J.

What is 1 J in kJ?

1 J = 0.001 kJ (see the value page for the full arithmetic).