Energy

J to kJ conversion

Convert joule (J) to kilojoule (kJ). Energy is the capacity to do work or transfer heat — the currency of every heat and material balance.

1 J = 0.001 kJ

Formula

To convert joule to kilojoule, multiply the J value by 0.001. To go the other way, divide by 0.001 (or multiply by 1000).

J to kJ conversion table

JkJ
10.001
20.002
50.005
100.01
250.025
500.05
1000.1
2500.25
5000.5
10001

Used in practice

Heat duties integrate to energy in kJ, MJ, or BTU; utilities are billed in kWh or MMBTU.

A calorie, a BTU, and a joule are all energy — keep the conversion factors handy when a spec mixes them.

Worked example. A energy of 3600000 J is 3600 kJ.

Frequently asked questions

How do you convert joule to kilojoule?

Multiply the value in J by 0.001 to get kJ. For example, 10 J = 0.01 kJ.

What is 1 J in kJ?

1 J equals 0.001 kJ.

Where is this conversion used?

Heat duties integrate to energy in kJ, MJ, or BTU; utilities are billed in kWh or MMBTU.

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