Megajoules to Joules Converter

One megajoule equals 1000000 joules (J). To convert megajoules to joules, multiply by 1000000; to go back the other way, multiply by 1.0000e-6 instead.

The converter above does it as you type and shows the working underneath, so you can check the arithmetic rather than take the number on trust.

What megajoules and joules actually measure

Megajoule (MJ) — A megajoule is a million joules. Fuel energy content and industrial process heat.

Joule (J) — The joule is the SI unit of energy — one watt for one second. Physics, mechanical work and food energy in most of the world.

Megajoules to Joules conversion table

The most common values, worked out in advance. Anything not listed can be typed straight into the converter.

How to convert megajoules to joules by hand

Multiply the number of megajoules by 1000000.

For example, 25 MJ × 1000000 = 25000000 J.

Going the other way, divide by 1000000 — or multiply by 1.0000e-6, which is the same thing and easier to do in your head.

Everything runs in your browser

There is no server involved in the calculation. The numbers you type never leave your device, nothing is logged, and the page keeps working with no connection once it has loaded. That is not a marketing line — it is simply how the tool is built, because a calculation like this has no reason to touch a network.