Joules (J) to Megajoules (MJ) Conversion
Joules
The joule (J) is the SI derived unit of energy, work, and heat, defined as the work done when a force of one newton displaces an object by one metre (J = N·m = kg·m²·s⁻²). Named after James Prescott Joule, who established the mechanical equivalent of heat in the 1840s, the joule unifies all forms of energy — mechanical, thermal, electrical, chemical, and nuclear — under one framework. One joule is small: lifting an apple (≈100 g) one metre requires about 1 joule, while a human at rest metabolises approximately 80 joules per second.
Megajoules
The megajoule (MJ) is a unit of energy equal to exactly 1,000,000 joules (10⁶ J). It is used in energy policy, engineering, and physics for large-scale energy quantities. One kilowatt-hour (kWh) equals exactly 3.6 MJ — the conversion fundamental to understanding electricity bills. A litre of petrol contains approximately 34 MJ of chemical energy. The explosive yield of conventional explosives is sometimes expressed in megajoules.
| Joules (J) | Megajoules (MJ) |
|---|---|
| 0.1 J | 0.0000001 MJ |
| 1 J | 0.000001 MJ |
| 2 J | 0.000002 MJ |
| 3 J | 0.000003 MJ |
| 5 J | 0.000005 MJ |
| 10 J | 0.00001 MJ |
| 20 J | 0.00002 MJ |
| 30 J | 0.00003 MJ |
| 50 J | 0.00005 MJ |
| 100 J | 0.0001 MJ |
| 1000 J | 0.001 MJ |
Frequently Asked Questions (FAQ)
How many megajoules are in 1 joules?
1 joules (J) is exactly 0.000001 megajoules (MJ).
How do I convert joules to megajoules?
Multiply the value in joules by 0.000001 to get the result in megajoules. Or use the converter above — type any number and see the result instantly.