Joule to Watt-Hour Converter
Convert Joule (J) to Watt-Hour (Wh) instantly. 1 J = 0.000278 Wh.
Energy Converter
27 units available
1 J = 0.000278 Wh
Formula:
Wh = J × 0.0002777778With your value: 1 J = 0.00027778 Wh
How big is that?
Everyday references on a logarithmic scale, all expressed in joule so you can sanity-check the result.
Other Joule to Watt-Hour conversions
Joule to Watt-Hour Conversion Table
| Joule (J) | Watt-Hour (Wh) |
|---|---|
| 0.5 | 0.000139 |
| 1 | 0.000278 |
| 2 | 0.000556 |
| 5 | 0.001389 |
| 10 | 0.002778 |
| 15 | 0.004167 |
| 20 | 0.005556 |
| 25 | 0.006944 |
| 50 | 0.013889 |
| 100 | 0.027778 |
| 250 | 0.069444 |
| 500 | 0.138889 |
| 1000 | 0.277778 |
Watt-Hour to Joule Conversion Table
| Watt-Hour (Wh) | Joule (J) |
|---|---|
| 0.5 | 1,800 |
| 1 | 3,600 |
| 2 | 7,200 |
| 5 | 18,000 |
| 10 | 36,000 |
| 15 | 54,000 |
| 20 | 72,000 |
| 25 | 90,000 |
| 50 | 180,000 |
| 100 | 360,000 |
| 250 | 900,000 |
| 500 | 1,800,000 |
| 1000 | 3,600,000 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
Joule (J)
Energy
Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.
Source: NIST Special Publication 811, Guide for the Use of the International System of Units
National Institute of Standards and Technology (US) · Reviewed 2026-07-01
Watt-Hour (Wh)
Energy
Derived from the joule (1 J = 1 kg·m²/s²). Thermochemical and IT calories, BTU and kWh are exact defined multiples.
Source: NIST Special Publication 811, Guide for the Use of the International System of Units
National Institute of Standards and Technology (US) · Reviewed 2026-07-01
How to Convert Joule to Watt-Hour
To convert from Joule (J) to Watt-Hour (Wh), multiply the value by 0.0002777778.
Formula: Wh = J × 0.0002777778
Reverse: J = Wh × 3,600
Step-by-Step Example
- Start with your value in Joule. For example: 5 J
- Multiply by the conversion factor: 5 x 0.0002777778
- The result is: 0.001389 Wh
About Joule
The joule is the SI unit of energy. One joule equals the work done when a force of one newton moves an object one meter.
Common uses: physics, electrical engineering, chemistry.
About Watt-Hour
The watt-hour (Wh) is a unit of energy and work. One watt-hour equals 3600 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
Common uses: energy calculations, engineering and science, education.
Frequently Asked Questions
How many Watt-Hour are in 1 Joule?
There are exactly 0.0002777778 Watt-Hour in 1 Joule. This means the conversion factor from Joule to Watt-Hour is 0.0002777778.
What is the formula to convert Joule to Watt-Hour?
The formula to convert Joule to Watt-Hour is: Wh = J × 0.0002777778. For example, to convert 10 Joule to Watt-Hour, you would multiply 10 by 0.0002777778.
What is a Joule?
The joule is the SI unit of energy. One joule equals the work done when a force of one newton moves an object one meter.
What is a Watt-Hour?
The watt-hour (Wh) is a unit of energy and work. One watt-hour equals 3600 joules. UnitConvertLab converts it against every other energy unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
What are the common uses of Joule?
The Joule is commonly used in physics, electrical engineering, chemistry.
Related Energy Conversions
Cite this page
UnitConvertLab. (2026). Joule to Watt-Hour converter. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/joule-to-watt_hour