⚡ Energy
kilojoules to joules Converter
Convert kilojoules to joules instantly with a reference conversion table.
Quick answer: To convert kilojoules to joules, multiply by 1000. For example, 1 kilojoules = 1000 joules. Use the calculator below for any value.
kilojoules to joules
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Common conversions
| kilojoules | joules |
|---|
Formula:
How to convert kilojoules to joules
1
Enter your value
Type the number of kilojoules you want to convert into the left box. The result in joules appears instantly in the right box. You can also type into the right box to convert in the other direction.
2
Use the swap button
Click the ⇄ Swap button to reverse the conversion — joules to kilojoules. Your current value carries across so you don't have to re-enter anything.
3
About kilojoules and joules
kilojoules and joules are common energy measurements.
💡 Did you know?
1 kJ = 1,000 J. The joule (J) is the SI base unit of energy. 1 joule is defined as the energy transferred when 1 newton of force acts over 1 metre. James Prescott Joule (1818–1889) established the equivalence of heat and mechanical work — the foundation of thermodynamics.
📊 Common conversions at a glance
| kilojoules | joules |
|---|---|
| 0.001 | 1 |
| 0.01 | 10 |
| 0.1 | 100 |
| 0.5 | 500 |
| 1 | 1000 |
| 2 | 2000 |
Reviewed for 2026. kilojoules ↔ joules conversion factor verified against published reference data. Built by a UK-based qualified primary teacher and FA Level 2 coach as part of 247QuickTools' free utility-tools project.