Quick answer: 1 Joule in Watt-hour (Wh)
1 J equals 0.000277778 Wh. To convert Joule to Watt-hour (Wh), multiply by 0.000277778 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 Joule in Watt-hour (Wh)?
- Multiply 1 by the conversion factor 0.000277778
- 1 Joule = 0.000277778 Watt-hour (Wh)
How much is 100 Joule in Watt-hour (Wh)?
- Multiply 100 by the conversion factor 0.000277778
- 100 Joule = 0.0277778 Watt-hour (Wh)
How much is 1000 Joule in Watt-hour (Wh)?
- Multiply 1000 by the conversion factor 0.000277778
- 1000 Joule = 0.277778 Watt-hour (Wh)
Quick Conversion Reference Table
| Joule (J) | Watt-hour (Wh) (Wh) |
|---|---|
| 1 J (Joule) | 0.000277778 Wh (Watt-hour (Wh)) |
| 2 J (Joule) | 0.000555556 Wh (Watt-hour (Wh)) |
| 5 J (Joule) | 0.00138889 Wh (Watt-hour (Wh)) |
| 10 J (Joule) | 0.00277778 Wh (Watt-hour (Wh)) |
| 20 J (Joule) | 0.00555556 Wh (Watt-hour (Wh)) |
| 50 J (Joule) | 0.0138889 Wh (Watt-hour (Wh)) |
| 100 J (Joule) | 0.0277778 Wh (Watt-hour (Wh)) |
| 500 J (Joule) | 0.138889 Wh (Watt-hour (Wh)) |
| 1000 J (Joule) | 0.277778 Wh (Watt-hour (Wh)) |
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FAQ
How much is 1 Joule in Watt-hour (Wh)?
1 Joule = 0.000277778 Watt-hour (Wh).
How do I convert Joule to Watt-hour (Wh)?
Enter your value in Joule into the converter above and the result in Watt-hour (Wh) appears instantly. 1 J equals 0.000277778 Wh — just multiply your value by 0.000277778.
What is the formula for Joule to Watt-hour (Wh)?
The formula is: value in Watt-hour (Wh) = value in Joule × 0.000277778. For example, 100 J × 0.000277778 = 0.0277778 Wh.
Is this Joule to Watt-hour (Wh) converter free and accurate?
Yes. This Joule to Watt-hour (Wh) converter is 100% free, uses the exact international conversion factor (0.000277778), and works on any device with no signup.
How do I convert Watt-hour (Wh) back to Joule?
To convert back, divide by 0.000277778 (or multiply by 3600). You can also use our dedicated How Many Joule 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.