Megajoules to joules

Type a value in megajoules to see it in joules straight away, or type in the second box to convert back.

Loading the tool…

Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.

How to use it

  1. Type the value in the megajoules box.
  2. Read the result in joules as you type, and pick the precision you need.
  3. Swap the direction to convert back, or copy the result.

How it is calculated

J = MJ × 1,000,000

Multiply the value in megajoules by 1,000,000 to get joules.

Example

To convert 25 MJ to joules: 25 × 1,000,000 = 25,000,000 J.

Conversion table

Megajoules (MJ)Joules (J)
11,000,000
22,000,000
33,000,000
55,000,000
1010,000,000
2020,000,000
2525,000,000
5050,000,000
100100,000,000
250250,000,000
500500,000,000
1,0001,000,000,000

About the units

Megajoule
Exactly one million joules, used for the heating value of fuels and gas.
Joule
The SI unit of energy, equal to the work done by a force of one newton moving an object one meter.

Limits and caveats

  • Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
  • Both unit factors are exact by their official definitions.

Questions about this tool

How many joules are in one megajoule?

1 MJ = 1,000,000 J exactly.

How do I convert megajoules to joules?

Use J = MJ × 1,000,000. For example, 25 MJ = 25,000,000 J.

How many megajoules are in one joule?

1 J = 0.000001 MJ.

Which calorie do these converters use?

The thermochemical calorie, exactly 4.184 joules, the factor many countries use to turn kcal into kJ on food labels. The International Table calorie is 4.1868 joules, less than 0.07% larger.

What is the difference between kW and kWh?

A kilowatt is a unit of power, the rate of using energy, while a kilowatt-hour is an amount of energy. A 2 kW heater running for three hours uses 6 kWh.