Convert joules to kilowatt-hours
Converting joules to kilowatt-hours is a common energy task, whether you are checking a recipe, a spec sheet, a travel distance or a homework problem. Since 1 J equals 0.000000277778 kWh, the math is a single multiplication — and this page does it for you instantly, with the formula, a table of common values and answers to the questions people ask most.
Exact factor
How to convert joules to kilowatt-hours
To convert joules to kilowatt-hours, multiply the number of joules by 0.000000277778. For example, 10 J × 0.000000277778 = 0.00000277778 kWh.
kWh = J × 0.000000277778
- Write down the value in joules you want to convert.
- Multiply it by 0.000000277778 (the exact J→kWh factor).
- The result is your value in kilowatt-hours. Check it below with the converter or the table.
Conversion table
Common values of joules and their equivalents in kilowatt-hours:
| J | kWh |
|---|---|
| 1 | 0.000000277778 |
| 2 | 0.000000555556 |
| 3 | 0.000000833333 |
| 4 | 0.00000111111 |
| 5 | 0.00000138889 |
| 10 | 0.00000277778 |
| 20 | 0.00000555556 |
| 25 | 0.00000694444 |
| 50 | 0.0000138889 |
| 100 | 0.0000277778 |
| 250 | 0.0000694444 |
| 500 | 0.000138889 |
About these units
Joule (J). The joule is the SI unit of energy: the work done by one newton acting over one meter. Food labels in most countries, physics and engineering use joules.
Kilowatt-hour (kWh). A kilowatt-hour is the energy delivered by one kilowatt over one hour, exactly 3.6 million joules. Household electricity bills and EV batteries are measured in kWh.
Frequently asked questions
How do I convert joules to kilowatt-hours?
To convert joules to kilowatt-hours, multiply the number of joules by 0.000000277778. For example, 10 J × 0.000000277778 = 0.00000277778 kWh. Or skip the math: type the value into the converter at the top of this page and the result updates instantly.
How many kilowatt-hours are in 1 joule?
1 J = 0.000000277778 kWh. That is the fixed relationship used by this converter and by international standards.
How many joules are in 1 kilowatt-hour?
1 kWh = 3,600,000 J. If you are converting in the opposite direction, use our Kilowatt-hour to Joule converter for the dedicated table and FAQ.
Is the joules to kilowatt-hours conversion exact?
Yes. Both units are defined by international agreement, so the factor of 0.000000277778 is exact. Displayed results are rounded to 6 significant digits only for readability.
What is joule used for?
The joule is the SI unit of energy: the work done by one newton acting over one meter. Food labels in most countries, physics and engineering use joules.