Convert kilowatt-hours to joules
Converting kilowatt-hours to joules is a common energy task, whether you are checking a recipe, a spec sheet, a travel distance or a homework problem. Since 1 kWh equals 3,600,000 J, 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 kilowatt-hours to joules
To convert kilowatt-hours to joules, multiply the number of kilowatt-hours by 3,600,000. For example, 10 kWh × 3,600,000 = 36,000,000 J.
J = kWh × 3,600,000
- Write down the value in kilowatt-hours you want to convert.
- Multiply it by 3,600,000 (the exact kWh→J factor).
- The result is your value in joules. Check it below with the converter or the table.
Conversion table
Common values of kilowatt-hours and their equivalents in joules:
| kWh | J |
|---|---|
| 1 | 3,600,000 |
| 2 | 7,200,000 |
| 3 | 10,800,000 |
| 4 | 14,400,000 |
| 5 | 18,000,000 |
| 10 | 36,000,000 |
| 20 | 72,000,000 |
| 25 | 90,000,000 |
| 50 | 180,000,000 |
| 100 | 360,000,000 |
| 250 | 900,000,000 |
| 500 | 1,800,000,000 |
About these units
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.
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.
Frequently asked questions
How do I convert kilowatt-hours to joules?
To convert kilowatt-hours to joules, multiply the number of kilowatt-hours by 3,600,000. For example, 10 kWh × 3,600,000 = 36,000,000 J. Or skip the math: type the value into the converter at the top of this page and the result updates instantly.
How many joules are in 1 kilowatt-hour?
1 kWh = 3,600,000 J. That is the fixed relationship used by this converter and by international standards.
How many kilowatt-hours are in 1 joule?
1 J = 0.000000277778 kWh. If you are converting in the opposite direction, use our Joule to Kilowatt-hour converter for the dedicated table and FAQ.
Is the kilowatt-hours to joules conversion exact?
Yes. Both units are defined by international agreement, so the factor of 3,600,000 is exact. Displayed results are rounded to 6 significant digits only for readability.
What is kilowatt-hour used for?
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.