Quick answer: 1 Kilojoule in Watt-hour (Wh)
1 kJ equals 0.277778 Wh. To convert Kilojoule to Watt-hour (Wh), multiply by 0.277778 using the free calculator above — no signup needed.
Energy & Work units
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About Energy & Work Converter
The Energy & Work Converter converts between 7 different units, including Joule, Kilojoule, Calorie, Kilocalorie (kcal), Watt-hour (Wh). The base unit is the Joule, and every other unit on this page is defined as an exact multiple of it. Type any value into the calculator above to convert instantly — free, unlimited, no signup and nothing to install.
Common equivalents: 1 Joule = 0.001 Kilojoule, 0.239006 Calorie, 0.000239006 Kilocalorie (kcal).
Scale of this category: the smallest unit is the Joule (J) and the largest is the Kilowatt-hour (kWh) (kWh).
Last updated: 2026-09-15
Energy & Work conversion factors
| Unit | Symbol | Value in Joule |
|---|---|---|
| Joule | J | 1 J = 1 J |
| Kilojoule | kJ | 1 kJ = 1000 J |
| Calorie | cal | 1 cal = 4.184 J |
| Kilocalorie (kcal) | kcal | 1 kcal = 4184 J |
| Watt-hour (Wh) | Wh | 1 Wh = 3600 J |
| Kilowatt-hour (kWh) | kWh | 1 kWh = 3600000 J |
| BTU | BTU | 1 BTU = 1055.06 J |
Worked Examples
See exactly how the conversion works with real numbers, step by step.
How much is 1 Kilojoule in Watt-hour (Wh)?
- Multiply 1 by the conversion factor 0.277778
- 1 Kilojoule = 0.277778 Watt-hour (Wh)
How much is 10 Kilojoule in Watt-hour (Wh)?
- Multiply 10 by the conversion factor 0.277778
- 10 Kilojoule = 2.777778 Watt-hour (Wh)
How much is 100 Kilojoule in Watt-hour (Wh)?
- Multiply 100 by the conversion factor 0.277778
- 100 Kilojoule = 27.777778 Watt-hour (Wh)
Quick Conversion Reference Table
| Kilojoule (kJ) | Watt-hour (Wh) (Wh) |
|---|---|
| 1 kJ (Kilojoule) | 0.277778 Wh (Watt-hour (Wh)) |
| 2 kJ (Kilojoule) | 0.555556 Wh (Watt-hour (Wh)) |
| 5 kJ (Kilojoule) | 1.388889 Wh (Watt-hour (Wh)) |
| 10 kJ (Kilojoule) | 2.777778 Wh (Watt-hour (Wh)) |
| 20 kJ (Kilojoule) | 5.555556 Wh (Watt-hour (Wh)) |
| 50 kJ (Kilojoule) | 13.888889 Wh (Watt-hour (Wh)) |
| 100 kJ (Kilojoule) | 27.777778 Wh (Watt-hour (Wh)) |
| 500 kJ (Kilojoule) | 138.888889 Wh (Watt-hour (Wh)) |
| 1000 kJ (Kilojoule) | 277.777778 Wh (Watt-hour (Wh)) |
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FAQ
How much is 1 Kilojoule in Watt-hour (Wh)?
1 Kilojoule = 0.277778 Watt-hour (Wh).
How do I convert Kilojoule to Watt-hour (Wh)?
Enter your value in Kilojoule into the converter above and the result in Watt-hour (Wh) appears instantly. 1 kJ equals 0.277778 Wh — just multiply your value by 0.277778.
What is the formula for Kilojoule to Watt-hour (Wh)?
The formula is: value in Watt-hour (Wh) = value in Kilojoule × 0.277778. For example, 10 kJ × 0.277778 = 2.777778 Wh.
Is this Kilojoule to Watt-hour (Wh) converter free and accurate?
Yes. This Kilojoule to Watt-hour (Wh) converter is 100% free, uses the exact international conversion factor (0.277778), and works on any device with no signup.
How do I convert Watt-hour (Wh) back to Kilojoule?
To convert back, divide by 0.277778 (or multiply by 3.6). You can also use our dedicated How Many Kilojoule in 1 Watt-hour (Wh)? page for instant results.
Do I need to download an app or sign up?
No. The converter runs entirely in your browser — nothing to install, no account, no fees. It even keeps working offline once the page has loaded.
Which Energy & Work units are supported?
This converter supports 7 units: Joule, Kilojoule, Calorie, Kilocalorie (kcal), Watt-hour (Wh), Kilowatt-hour (kWh), BTU.