/convert/joules-to-kilojoules/ Convert joules to kilojoules instantly. Includes a reference table and formula. article joules to kilojoules Converter — 247QuickTools ,{ "@context": "https://schema.org", "@type": "SpeakableSpecification", "cssSelector": [".tool-intro", ".info-gain-section"] }
⚡ Energy

joules to kilojoules Converter

Convert joules to kilojoules instantly. Includes a reference table and formula.

Quick answer: To convert joules to kilojoules, multiply by 0.001. For example, 1 joules = 0.001 kilojoules. Use the calculator below for any value.
joules to kilojoules
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Common conversions
joules kilojoules
Formula:

How to convert joules to kilojoules

1

Enter your value

Type the number of joules you want to convert into the left box. The result in kilojoules 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 — kilojoules to joules. Your current value carries across so you don't have to re-enter anything.

3

About joules and kilojoules

joules and kilojoules are both energy. Use this converter to switch between them instantly.

💡 Did you know?

1 kJ = 1,000 J. A food Calorie (kcal) = 4.184 kJ. EU food labels use kJ: 2,000 kcal = 8,368 kJ per day. A lightning bolt releases about 1 billion J = 1 GJ. A 1 kWh of electricity = 3,600 kJ = 860 kcal — roughly equivalent to the energy in a Mars Bar.

📊 Common conversions at a glance
joules kilojoules
100 0.1
500 0.5
1000 1
2000 2
5000 5
10000 10
Reviewed for 2026. joules ↔ kilojoules 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.