Watt-hours to joules
Type a value in watt-hours to see it in joules straight away, or type in the second box to convert back.
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How to use it
- Type the value in the watt-hours box.
- Read the result in joules as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
J = Wh × 3,600
Multiply the value in watt-hours by 3,600 to get joules.
Example
To convert 25 Wh to joules: 25 × 3,600 = 90,000 J.
Conversion table
| Watt-hours (Wh) | Joules (J) |
|---|---|
| 1 | 3,600 |
| 2 | 7,200 |
| 3 | 10,800 |
| 5 | 18,000 |
| 10 | 36,000 |
| 20 | 72,000 |
| 25 | 90,000 |
| 50 | 180,000 |
| 100 | 360,000 |
| 250 | 900,000 |
| 500 | 1,800,000 |
| 1,000 | 3,600,000 |
About the units
- Watt-hour
- The energy used by a one watt device in one hour, exactly 3600 joules. Common for battery and power bank capacity.
- Joule
- The SI unit of energy, equal to the work done by a force of one newton moving an object one meter.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many joules are in one watt-hour?
1 Wh = 3,600 J exactly.
How do I convert watt-hours to joules?
Use J = Wh × 3,600. For example, 25 Wh = 90,000 J.
How many watt-hours are in one joule?
1 J = 0.000277778 Wh.
Which calorie do these converters use?
The thermochemical calorie, exactly 4.184 joules, the factor many countries use to turn kcal into kJ on food labels. The International Table calorie is 4.1868 joules, less than 0.07% larger.
What is the difference between kW and kWh?
A kilowatt is a unit of power, the rate of using energy, while a kilowatt-hour is an amount of energy. A 2 kW heater running for three hours uses 6 kWh.