Kilowatt-hours to Joules (kWh to J) Converter
1 kilowatt-hour equals 3,600,000 joules — multiply kilowatt-hours by 3,600,000 to convert. One watt is one joule per second, so a kilowatt (1,000 W) sustained for one hour (3,600 s) delivers 1,000 × 3,600 = 3.6 million joules, also written as 3.6 megajoules.
The formula
Multiply the kilowatt-hour value by 3,600,000 to get joules:
J = kWh × 3,600,000
For example, 2.5 kWh × 3,600,000 = 9,000,000 J. To reverse, divide joules by 3,600,000.
Conversion table
| Kilowatt-hours (kWh) | Joules (J) |
|---|---|
| 1 | 3,600,000 |
| 2 | 7,200,000 |
| 5 | 18,000,000 |
| 10 | 36,000,000 |
| 25 | 90,000,000 |
| 50 | 180,000,000 |
| 100 | 360,000,000 |
| 500 | 1,800,000,000 |
| 1000 | 3,600,000,000 |
How to convert online
- Type the number of kilowatt-hours in the first box.
- Read the joule result instantly in the second box.
- Enter a joule value to convert the other way — it works both directions.
Use the Kilowatt-hour to Joule Converter — free and instant in your browser.
Where this conversion is used
Utility bills measure electricity in kilowatt-hours, but physics and engineering work in joules, the SI unit of energy. Converting between them is essential when calculating the energy content of a battery, comparing electrical consumption to mechanical work, or solving thermodynamics and circuit problems where textbook values are in joules but real-world usage is metered in kWh.
FAQ
How many joules are in a kWh?
One kWh equals 3,600,000 joules (3.6 MJ). Multiply the kWh figure by 3,600,000 — for example, 10 kWh = 36,000,000 J.
What is the formula to convert kWh to joules?
Use J = kWh × 3,600,000. The tool applies this exact factor automatically so you never round by hand.
How do I convert joules back to kWh?
Divide by 3,600,000 (or multiply by 2.777778e-7). For instance, 36,000,000 J = 10 kWh.
Is the conversion exact?
Yes. A kWh is exactly 1,000 W × 3,600 s = 3,600,000 J by definition, with no rounding.
Related converters
- Joule to Kilowatt-hour Converter
- Kilowatt-hour to Kilojoule Converter
- Kilowatt-hour to Calorie Converter
- Kilowatt-hour to Watt-hour Converter
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