Kilowatt Hours to Megajoules
A kilowatt-hour is 1,000 watt-hours, the unit electricity companies use to bill household power usage. A megajoule is one million joules, used to measure the energy content of fuels and large-scale energy use. 1 kWh equals 3.6 MJ, so converting between them is a matter of multiplying by that fixed factor — type any value into the converter below and both sides update instantly as you type.
Both units belong to energy, measured here against energy's base unit (J) — every other energy unit on this site converts through that same reference point, which is why the table below can also be read as a quick cross-check against nearby values.
Formula
MJ = kWh × 3.6
kWh = MJ × ≈0.277778
Worked example: 5 kWh × 3.6 = 18 MJ.
Conversion table
| Kilowatt-hour (kWh) | Megajoule (MJ) |
|---|---|
| 1 kWh | 3.6 MJ |
| 2 kWh | 7.2 MJ |
| 3 kWh | 10.8 MJ |
| 5 kWh | 18 MJ |
| 10 kWh | 36 MJ |
| 20 kWh | 72 MJ |
| 25 kWh | 90 MJ |
| 50 kWh | 180 MJ |
| 100 kWh | 360 MJ |
| 250 kWh | 900 MJ |
| 500 kWh | 1,800 MJ |
| 1,000 kWh | 3,600 MJ |
Frequently asked
- How many Megajoules in a kilowatt-hour?
- 1 kWh equals 3.6 MJ.
- How do I convert Kilowatt-hours to Megajoules?
- Multiply the value in kWh by 3.6 to get MJ. The converter above does this instantly as you type.
- Is the conversion exact?
- Yes — Kilowatt-hour and Megajoule are both defined by a fixed conversion factor to energy's base unit (J), so the result shown is exact to the precision displayed, not an approximation.