How to convert megajoules to kilowatt-hours
One megajoule equals 0.277778 kilowatt-hours, so multiply the number of megajoules by 0.277778:
kWh = MJ × 0.277778
MJ = kWh ÷ 0.277778 (1 kWh = 3.6 MJ)
Example: 3.6 MJ → 3.6 × 0.277778 = 1 kWh.
Going the other way, divide by 0.277778, or multiply by 3.6; the kilowatt-hours to megajoules converter does it for you.
Everyday values
| Megajoules | Kilowatt-hours | For example |
|---|---|---|
| 3.6 MJ | 1 kWh | one kilowatt-hour |
| 10 MJ | 2.7778 kWh | 10 MJ |
| 34 MJ | 9.4444 kWh | the energy in a litre of petrol, roughly |
When you need this conversion
Divide megajoules by 3.6 to get kWh. Gas bills in some countries show energy in MJ, while electricity bills use kWh, so converting lets you compare the two.
Megajoule to kilowatt-hour conversion table
| MJ | kWh | MJ | kWh |
|---|---|---|---|
| 1 MJ | 0.277778 kWh | 13 MJ | 3.6111 kWh |
| 2 MJ | 0.555556 kWh | 14 MJ | 3.8889 kWh |
| 3 MJ | 0.833333 kWh | 15 MJ | 4.1667 kWh |
| 4 MJ | 1.1111 kWh | 16 MJ | 4.4444 kWh |
| 5 MJ | 1.3889 kWh | 17 MJ | 4.7222 kWh |
| 6 MJ | 1.6667 kWh | 18 MJ | 5 kWh |
| 7 MJ | 1.9444 kWh | 19 MJ | 5.2778 kWh |
| 8 MJ | 2.2222 kWh | 20 MJ | 5.5556 kWh |
| 9 MJ | 2.5 kWh | 21 MJ | 5.8333 kWh |
| 10 MJ | 2.7778 kWh | 22 MJ | 6.1111 kWh |
| 11 MJ | 3.0556 kWh | 23 MJ | 6.3889 kWh |
| 12 MJ | 3.3333 kWh | 24 MJ | 6.6667 kWh |
About the units
- Megajoule (MJ): one million joules.
- Kilowatt-hour (kWh): one kilowatt for one hour, 3.6 megajoules; the unit on electricity bills.
Both are units of energy. The conversion factor comes from the exact definitions above, so the calculator is exact; results are only rounded for display (up to six significant digits).
Frequently asked questions
How many kilowatt-hours are in one megajoule?
One megajoule is 0.277778 kilowatt-hours. One kilowatt-hour is 3.6 megajoules.
How do I convert megajoules to kilowatt-hours?
Multiply the value in megajoules by 0.277778. To go back, divide by 0.277778.
What is 3.6 MJ in kilowatt-hours?
3.6 MJ = 1 kWh.
What is 10 MJ in kilowatt-hours?
10 MJ = 2.7778 kWh.
Sources
- NIST Special Publication 811 (2008), Guide for the Use of the International System of Units (SI), Appendix B: conversion factors.
- NIST Handbook 44 (2024), Appendix C: General tables of units of measurement.
Last reviewed 5 October 2026. Results are estimates; see our disclaimer.