Kilowatt Hours to Kilojoules
An instant kilowatt hours-to-kilojoules converter, with the formula and a reference table below.
| Kilowatt Hours | Kilojoules |
|---|---|
| 1 kWh | 3600 kJ |
| 2 kWh | 7200 kJ |
| 3 kWh | 10800 kJ |
| 5 kWh | 18000 kJ |
| 10 kWh | 36000 kJ |
| 25 kWh | 90000 kJ |
| 50 kWh | 180000 kJ |
| 100 kWh | 360000 kJ |
How to use
- Enter a value in the Kilowatt Hours field.
- The Kilojoules figure appears immediately — no button to press.
- Typing in the Kilojoules field converts back to Kilowatt Hours the same way.
- Use the reference table for the values that come up most often.
Kilowatt Hours to Kilojoules formula
Converting kilowatt hours to kilojoules is a single multiplication by 3600.
kJ = kWh × 3600
Put another way, one kilowatt-hour is exactly 3,600 kilojoules.
Why this factor: the kilowatt-hour and the kilojoule are both defined against the joule, so dividing one definition by the other gives 3600 directly. Both definitions are set out in full below.
To go the other way, divide by 3600 — or use the Kilojoules to Kilowatt Hours converter, which is the same calculation reversed.
Worked example
Take 2000 kWh and multiply by the factor 3600: the result is 7200000 kJ.
2000 kWh × 3600 = 7200000 kJ
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 kilojoule?
A kilojoule is 1,000 joules, the metric unit of food energy.
Definition: Exactly 1,000 joules.
Where it is used: Nutrition labels in Europe and Australia, and heating and cooling loads.
Kilowatt Hours vs Kilojoules
The kilowatt-hour is a specialized unit while the kilojoule is a metric 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 kilojoules are in a kilowatt-hour?
One kilowatt-hour equals 3600 kilojoules.
What is the formula to convert kilowatt hours to kilojoules?
Multiply the number of kilowatt hours by 3600. To reverse it, divide by 3600 instead.
How do I convert kilojoules back to kilowatt hours?
Divide by 3600, which is the same as multiplying by 0.000277777778.
How many kilojoules are in 10 kilowatt hours?
10 kWh works out to 36000 kJ.
How is the kilowatt-hour defined?
Exactly 3.6 megajoules.