Kilowatt Hours to Joules
Type a value in either box to convert between kilowatt hours and joules. The factor is 3.6e+06.
| Kilowatt Hours | Joules |
|---|---|
| 1 kWh | 3600000 J |
| 2 kWh | 7200000 J |
| 3 kWh | 10800000 J |
| 5 kWh | 18000000 J |
| 10 kWh | 36000000 J |
| 25 kWh | 90000000 J |
| 50 kWh | 180000000 J |
| 100 kWh | 360000000 J |
How to use
- Enter a value in the Kilowatt Hours field.
- The Joules figure appears immediately — no button to press.
- Typing in the Joules field converts back to Kilowatt Hours the same way.
- Use the reference table for the values that come up most often.
Kilowatt Hours to Joules formula
Converting kilowatt hours to joules is a single multiplication by 3600000.
J = kWh × 3600000
Why this factor: the kilowatt-hour and the joule are both defined against the joule, so dividing one definition by the other gives 3600000 directly. Both definitions are set out in full below.
To go the other way, divide by 3600000 — or use the Joules to Kilowatt Hours converter, which is the same calculation reversed.
Worked example
Take 2000 kWh and multiply by the factor 3600000: the result is 7200000000 J.
2000 kWh × 3600000 = 7200000000 J
The converter above does this for any value you type, in either direction.
What is a kilowatt-hour?
A kilowatt-hour is the standard billing unit for electricity — one kilowatt drawn for one hour.
Definition: Exactly 3.6 megajoules.
Where it is used: Electricity bills worldwide, solar generation figures, and electric vehicle battery capacity.
What is a joule?
The joule is the SI unit of energy — the work done by one newton acting over one meter.
Definition: Defined as 1 N·m, equivalently one watt-second. Named after James Prescott Joule.
Where it is used: All scientific energy calculations, food energy on European labels, and mechanical work.
Kilowatt Hours vs Joules
The kilowatt-hour is a specialized unit while the joule is an SI unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many joules are in a kilowatt-hour?
One kilowatt-hour equals 3600000 joules.
What is the formula to convert kilowatt hours to joules?
Multiply the number of kilowatt hours by 3600000. To reverse it, divide by 3600000 instead.
How do I convert joules back to kilowatt hours?
Divide by 3600000, which is the same as multiplying by 2.77777778e-07.
How many joules are in 10 kilowatt hours?
10 kWh works out to 36000000 J.
How is the kilowatt-hour defined?
Exactly 3.6 megajoules.