Energy

kJ to J conversion

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

1 kJ = 1000 J

Formula

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

kJ to J conversion table

kJJ
11000
22000
55000
1010000
2525000
5050000
100100000
250250000
500500000
10001000000

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 3600 kJ is 3600000 J.

Frequently asked questions

How do you convert kilojoule to joule?

Multiply the value in kJ by 1000 to get J. For example, 10 kJ = 10000 J.

What is 1 kJ in J?

1 kJ equals 1000 J.

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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