Convert kilojoules to kilowatt-hours
Kilojoule (kJ) to kilowatt-hour (kWh). One kilojoule equals 0.000278 kilowatt-hours.
Formula
Kilojoule to kilowatt-hour conversion table
| Kilojoules | Kilowatt-hours | Kilowatt-hours | Kilojoules |
|---|---|---|---|
| 1 kJ | 0.000278 kWh | 1 kWh | 3600 kJ |
| 2 kJ | 0.000556 kWh | 2 kWh | 7200 kJ |
| 3 kJ | 0.000833 kWh | 3 kWh | 10800 kJ |
| 5 kJ | 0.001389 kWh | 5 kWh | 18000 kJ |
| 10 kJ | 0.002778 kWh | 10 kWh | 36000 kJ |
| 20 kJ | 0.005556 kWh | 20 kWh | 72000 kJ |
| 50 kJ | 0.013889 kWh | 50 kWh | 180000 kJ |
| 100 kJ | 0.027778 kWh | 100 kWh | 360000 kJ |
| 500 kJ | 0.138889 kWh | 500 kWh | 1800000 kJ |
| 1000 kJ | 0.277778 kWh | 1000 kWh | 3600000 kJ |
To convert kilojoules to kilowatt-hours, divide the number of kilojoules by 3600. One kilojoule equals 0.000278 kilowatt-hours, and one kilowatt-hour equals 3600 kilojoules, so the relationship is fixed and exact. As a worked example, 10 kJ comes to 0.002778 kWh. Enter your own figure in the converter above to get an instant answer, or use the swap button to flip the direction. This is a energy conversion, and like every tool on UnitGlide it runs locally in your browser with no account or upload required. The table further down shows a range of common kilojoule values already worked out in kilowatt-hours, plus the reverse kilowatt-hour to kilojoule direction, which is handy for quick reference or double-checking a result by hand.
Kilojoule to kilowatt-hour in practice
Kilojoules to kilowatt-hours rescales a raw energy figure into the unit utilities actually bill, which is handy when an appliance or process rates its consumption in joules.
Putting energy in billing terms
Some appliance and process datasheets state energy per cycle in kilojoules, while your bill is in kilowatt-hours, so an 1,800 kJ cycle is 0.5 kWh. Comparing a gas figure in kJ or MJ against an electricity tariff in kWh needs the same step before the running costs can be set side by side and the cheaper option picked.
Divide by 3,600
Because a kilowatt-hour is 3,600 kilojoules, you divide kJ by 3,600 to get kWh: 7,200 kJ is 2 kWh, and 3,600 kJ is exactly one. The mistake to avoid is confusing the energy in kJ with a power in kW; only an amount of energy converts to kilowatt-hours, never a rate.
Why the factor is 3,600
The number comes straight from the clock: an hour holds 3,600 seconds, and one kilojoule is a kilowatt sustained for a single second. Multiply that second up to a full hour and you have the 3,600-to-one ratio, which is the same reason a kilowatt-hour equals 3.6 megajoules.
Small kilojoule figures
Everyday appliance cycles land at small fractions of a kilowatt-hour, so expect answers well below one: a 900 kJ kettle boil is a quarter of a kWh, and a 360 kJ burst is a tenth. If a kilojoule figure produces a kWh number that looks large, the value was probably in megajoules rather than kilojoules.
Megajoules in the middle
Gas and heating energy often arrive in megajoules, a convenient rung between the two units here: one megajoule is 1,000 kJ and a shade over a quarter of a kWh. So a boiler rated at 30 MJ per hour is drawing about 8.3 kW, and passing through megajoules is frequently the clearest route from a kilojoule figure to a billable kilowatt-hour.
Frequently asked questions
How many kilowatt-hours are in a kilojoule?
One kilojoule equals 0.000278 kilowatt-hours. The ratio is constant, so you can multiply any number of kilojoules by 0.000278 to get kilowatt-hours.
What is the formula to convert kilojoules to kilowatt-hours?
Use kilowatt-hours = kilojoules ÷ 3600. UnitGlide applies this exact formula for every value, so results stay accurate across the whole range.
How do I convert kilowatt-hours back to kilojoules?
Go the other way by using one kilowatt-hour equals 3600 kilojoules. You can also press the swap button in the converter above to flip the direction in one click.
Is this kilojoule to kilowatt-hour converter accurate?
Yes. It uses internationally defined SI conversion factors, as maintained by the BIPM, and all math runs in your browser so nothing is rounded away on a server. For everyday use the displayed precision is more than enough.