Energy & Power

Megajoules to Kilowatt-hours

Convert megajoules to kilowatt-hours instantly. 1 MJ = 0.2777777778 kWh. Includes the exact factor, a conversion table of common values and the definition of both units.

MJ
Kilowatt-hours
One step, one exact factorMegajouleswhat you have× 0.2777777778Kilowatt-hourswhat you getBoth units are defined against the same base unit, so the factor is exact — never an approximation.

How to convert megajoules to kilowatt-hours

To convert megajoules to kilowatt-hours, divide by 3.6 (multiply by 0.2777777778). 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.

kWh = MJ × 0.2777777778

Megajoules to Kilowatt-hours conversion table

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

MegajoulesKilowatt-hours
1 MJ0.277778 kWh
2 MJ0.555556 kWh
3 MJ0.833333 kWh
5 MJ1.388889 kWh
10 MJ2.777778 kWh
20 MJ5.555556 kWh
25 MJ6.944444 kWh
50 MJ13.888889 kWh
100 MJ27.777778 kWh
500 MJ138.888889 kWh
1,000 MJ277.777778 kWh

What is a megajoule?

A million joules, used for fuel energy content and gas billing.

What is a kilowatt-hour?

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

The formula

kWh = MJ × 0.2777777778

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 Megajoules to Kilowatt-hours

  1. Type the number of megajoules you want to convert.
  2. Read the result in kilowatt-hours 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 kilowatt-hours to megajoules page.

Megajoules to Kilowatt-hours — frequently asked questions

How many kilowatt-hours are in a megajoule?

One megajoule equals 0.2777777778 kWh. kWh = MJ × 0.2777777778

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

The formula is kWh = MJ × 0.2777777778. It is an exact definition rather than an approximation, so the conversion never drifts no matter how large the number.

How do I convert kilowatt-hours back to megajoules?

Divide instead of multiplying: one kilowatt-hour is 3.6 MJ. 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 megajoules to kilowatt-hours 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