How many megajoules are in a kilowatt-hour?

One kilowatt-hour equals 3.6 megajoules exactly, because 1000 watts running for 3600 seconds is 3,600,000 joules, or 3.6 MJ.

How do I convert MJ back to kWh?

Divide megajoules by 3.6. For example, 18 MJ equals 18 ÷ 3.6 = 5 kWh. This tool does it for you when you pick the MJ to kWh direction.

Is anything sent to a server?

No — the conversion runs entirely in your browser and no data is uploaded.

How many kWh is 100 MJ?

100 MJ equals about 27.78 kWh (100 ÷ 3.6). Pick the MJ to kWh direction and the tool does the division for you.

Why is the kWh to MJ factor exactly 3.6?

A watt is one joule per second, so one kilowatt-hour is 1000 joules per second times 3600 seconds = 3,600,000 joules = 3.6 megajoules. It is an exact definition, not an approximation.

Where would I use this conversion?

Electricity bills are quoted in kWh, while gas energy content, scientific work and engineering specs often use megajoules. Converting between them lets you compare or sum energy from different sources.

kWh to MJ Converter — Gera Tools

kWh to MJ — the exact energy conversion

This converter turns kilowatt-hours (kWh), the unit on your electricity bill, into megajoules (MJ), the SI unit of energy, and back again. It is useful for comparing electricity use against gas energy content, sizing batteries, or checking engineering figures that mix the two units.

How it works

The factor is exact: a watt is one joule per second, so

1 kWh = 1000 W × 3600 s = 3,600,000 J = 3.6 MJ.

To convert kilowatt-hours to megajoules the tool multiplies by 3.6; to convert megajoules back to kilowatt-hours it divides by 3.6. You pick the direction and the result updates instantly.

Example

A household uses 12 kWh of electricity in a day. In megajoules:

12 × 3.6 = 43.2 MJ

So that day’s usage is 43.2 MJ. All maths runs in your browser, with nothing leaving your device.