Convert joules to Wh
Convert joules to watt-hours by entering a value below.
How to Convert Joules to Watt-hours
The joule and watt-hour are both units of energy. By definition, 1 watt-hour equals exactly 3600 joules. This means to convert joules to watt-hours, you divide by 3600.
Formula
Step-by-Step Example
Convert 5 J to watt-hours:
We need to convert joules to watt-hours
Since 1 Wh = 3600 J, divide by 3600
5 ÷ 3600 = 0.0013888889
5 J = 0.0013888889 Wh
Joule to Watt-hour Conversion Table
Quick reference table for common joule to watt-hour conversions. Click any value for detailed calculation.
| Joules (J) | Watt-hours (Wh) |
|---|---|
| 0.1 J | 2.7777777778e-5 Wh |
| 0.5 J | 0.0001388889 Wh |
| 1 J | 0.0002777778 Wh |
| 2 J | 0.0005555556 Wh |
| 5 J | 0.0013888889 Wh |
| 10 J | 0.0027777778 Wh |
| 25 J | 0.0069444444 Wh |
| 50 J | 0.0138888889 Wh |
| 100 J | 0.0277777778 Wh |
About These Units
Joule (J)
The joule (J) is the SI unit of energy equal to one watt-second or one newton-meter. Joules measure work, heat, and electrical energy. One joule equals approximately 0.239 calories. Lifting a 100g apple one meter requires about 1 joule. Named after physicist James Prescott Joule.
Watt-hour (Wh)
A watt-hour (Wh) is the energy of one watt sustained for one hour, equal to 3,600 joules. Watt-hours measure battery capacity (smartphone: 10-15 Wh, laptop: 50-100 Wh) and small appliance energy use. One Wh equals 3.6 kilojoules.
Frequently Asked Questions
How do I convert joules to watt-hours?
To convert joules to watt-hours, divide the value by 3600. For example, 10 J = 0.0027777778 Wh.
How many watt-hours are in 1 joule?
1 joule equals 0.0002777778 watt-hours.
What is the formula for joules to watt-hours?
The formula is: Wh = J ÷ 3600.