Joules to kilowatt-hours
Type a value in joules to see it in kilowatt-hours straight away, or type in the second box to convert back.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Type the value in the joules box.
- Read the result in kilowatt-hours as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
kWh = J × 2.777777778e-7
Multiply the value in joules by 2.777777778e-7 to get kilowatt-hours.
Example
To convert 25 J to kilowatt-hours: 25 × 2.777777778e-7 = 0.00000694444 kWh.
Conversion table
| Joules (J) | Kilowatt-hours (kWh) |
|---|---|
| 1 | 2.77778e-7 |
| 2 | 5.55556e-7 |
| 3 | 8.33333e-7 |
| 5 | 0.00000138889 |
| 10 | 0.00000277778 |
| 20 | 0.00000555556 |
| 25 | 0.00000694444 |
| 50 | 0.0000138889 |
| 100 | 0.0000277778 |
| 250 | 0.0000694444 |
| 500 | 0.000138889 |
| 1,000 | 0.000277778 |
About the units
- Joule
- The SI unit of energy, equal to the work done by a force of one newton moving an object one meter.
- Kilowatt-hour
- The energy used by a 1000 watt device in one hour, exactly 3.6 million joules. Electricity bills are charged in this unit.
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 kilowatt-hours are in one joule?
1 J = 2.77778e-7 kWh exactly.
How do I convert joules to kilowatt-hours?
Use kWh = J × 2.777777778e-7. For example, 25 J = 0.00000694444 kWh.
How many joules are in one kilowatt-hour?
1 kWh = 3,600,000 J.
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.