Joules to Kilowatt-hours (J to kWh) Converter
1 joule equals 2.777778e-7 kilowatt-hours — multiply joules by 2.777778e-7, or divide by 3,600,000, to convert J to kWh. One kilowatt-hour is the energy of 1,000 watts running for one hour, which works out to exactly 3,600,000 joules.
The formula
To convert joules to kilowatt-hours, multiply by the exact factor:
kWh = J × 2.777778e-7
For example, 3,600,000 J × 2.777778e-7 = 1 kWh. The factor is simply 1 ÷ 3,600,000.
Conversion table
| Joules (J) | Kilowatt-hours (kWh) |
|---|---|
| 1 | 0.00000027778 |
| 10 | 0.0000027778 |
| 100 | 0.000027778 |
| 1000 | 0.00027778 |
| 3600 | 0.001 |
| 10000 | 0.0027778 |
| 100000 | 0.027778 |
| 1000000 | 0.27778 |
| 3600000 | 1 |
How to convert online
- Type the number of joules into the first box.
- Read the kilowatt-hour result instantly in the second box.
- Or enter a kWh value to convert back to joules — it works both ways.
Use the Joule to Kilowatt-hour Converter — free and instant in your browser.
Where this conversion is used
Joules are the physicist's unit of energy, but utility companies bill electricity in kilowatt-hours. Converting between them is useful when you calculate the running cost of an appliance rated in watts, estimate battery capacity, or check physics homework against a real-world energy bill. Because a single kWh is 3.6 million joules, small joule figures translate into very small kWh fractions.
FAQ
How many kilowatt-hours are in a joule?
One joule equals 2.777778e-7 kWh — that is 0.00000027778 kWh, or one 3,600,000th of a kilowatt-hour.
How many joules are in 1 kWh?
Exactly 3,600,000 joules make up one kilowatt-hour.
How do I convert kWh back to joules?
Multiply the kilowatt-hour value by 3,600,000. For example, 2 kWh = 7,200,000 J.
Is the conversion exact?
Yes, though 2.777778e-7 is a rounded display of the exact fraction 1/3,600,000; the tool keeps full precision internally.
Related converters
- Kilowatt-hour to Joule Converter
- Joule to Kilojoule Converter
- Joule to Watt-hour Converter
- Joule to Kilocalorie Converter
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