Energy & Power

Kilowatt-hours to Kilojoules

Convert kilowatt-hours to kilojoules instantly. 1 kWh = 3,600 kJ. Includes the exact factor, a conversion table of common values and the definition of both units.

kWh
Kilojoules
One step, one exact factorKilowatt-hourswhat you have× 3,600Kilojouleswhat you getBoth units are defined against the same base unit, so the factor is exact — never an approximation.

How to convert kilowatt-hours to kilojoules

To convert kilowatt-hours to kilojoules, multiply by 3,600. The relationship is fixed, so the same factor works for any quantity — there is nothing to look up and nothing that changes with temperature, location or context.

kJ = kWh × 3,600

Kilowatt-hours to Kilojoules conversion table

The values people look up most often, rounded for reading. Use the calculator above for anything in between.

Kilowatt-hoursKilojoules
1 kWh3,600 kJ
2 kWh7,200 kJ
3 kWh10,800 kJ
5 kWh18,000 kJ
10 kWh36,000 kJ
20 kWh72,000 kJ
25 kWh90,000 kJ
50 kWh180,000 kJ
100 kWh360,000 kJ
500 kWh1,800,000 kJ
1,000 kWh3,600,000 kJ

What is a kilowatt-hour?

The unit on every electricity bill: a thousand watts for one hour.

What is a kilojoule?

A thousand joules. Food energy is labelled in kilojoules outside the US.

The formula

kJ = kWh × 3,600

Every result on this page comes from this formula. Nothing is rounded until the final display, so figures match a spreadsheet to the cent.

How to use the Kilowatt-hours to Kilojoules

  1. Type the number of kilowatt-hours you want to convert.
  2. Read the result in kilojoules straight away — there is no button to press.
  3. Check the table below for the values that come up most often, or reverse the conversion with the linked kilojoules to kilowatt-hours page.

Kilowatt-hours to Kilojoules — frequently asked questions

How many kilojoules are in a kilowatt-hour?

One kilowatt-hour equals 3,600 kJ. kJ = kWh × 3,600

What is the formula to convert kilowatt-hours to kilojoules?

The formula is kJ = kWh × 3,600. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.

How do I convert kilojoules back to kilowatt-hours?

Divide instead of multiplying: one kilojoule is 0.0002777778 kWh. The reverse converter is linked in the related tools list.

Is this conversion exact?

Yes. Both units are defined against the same base unit by international agreement, so the factor is exact — any rounding you see is only in the display, which you can widen by entering more decimal places.

Is this kilowatt-hours to kilojoules free to use?

Yes. Every calculator on the site is free, needs no sign-up, and runs entirely in your browser, so your figures never leave your device.

What people search for

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About this calculator

Written and reviewed by The Samsung Calculator editorial team. Every calculator is written against a published formula, reviewed against at least one independent reference implementation, and dated when it changes.

Last reviewed August 19, 2026 · Calculation runs client-side · No data collected · Report an error