Kilojoules to Kilowatt Hours
An instant kilojoules-to-kilowatt hours converter, with the formula and a reference table below.
| Kilojoules | Kilowatt Hours |
|---|---|
| 1 kJ | 0.000278 kWh |
| 2 kJ | 0.000556 kWh |
| 3 kJ | 0.000833 kWh |
| 5 kJ | 0.001389 kWh |
| 10 kJ | 0.002778 kWh |
| 25 kJ | 0.006944 kWh |
| 50 kJ | 0.013889 kWh |
| 100 kJ | 0.027778 kWh |
How to use
- Enter a value in the Kilojoules field.
- The Kilowatt Hours figure appears immediately — no button to press.
- Typing in the Kilowatt Hours field converts back to Kilojoules the same way.
- Use the reference table for the values that come up most often.
Kilojoules to Kilowatt Hours formula
The factor from kilojoules to kilowatt hours is 0.000277777778.
kWh = kJ × 0.000277777778
Put another way, one kilojoule is exactly 1/3,600 of a kilowatt-hour.
Why this factor: the kilojoule and the kilowatt-hour are both defined against the joule, so dividing one definition by the other gives 0.000277777778 directly. Both definitions are set out in full below.
To go the other way, divide by 0.000277777778 — or use the Kilowatt Hours to Kilojoules converter, which is the same calculation reversed.
Worked example
Given 500 kJ, multiplying by 0.000277777778 yields 0.138889 kWh.
500 kJ × 0.000277777778 = 0.138889 kWh
The converter above does this for any value you type, in either direction.
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.
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.
Kilojoules vs Kilowatt Hours
The kilojoule is a metric unit while the kilowatt-hour is a specialized 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 kilowatt hours are in a kilojoule?
One kilojoule equals 0.000277777778 kilowatt hours.
What is the formula to convert kilojoules to kilowatt hours?
Multiply the number of kilojoules by 0.000277777778. To reverse it, divide by 0.000277777778 instead.
How do I convert kilowatt hours back to kilojoules?
Divide by 0.000277777778, which is the same as multiplying by 3600.
How many kilowatt hours are in 10 kilojoules?
10 kJ works out to 0.002778 kWh.
How is the kilojoule defined?
Exactly 1,000 joules.