Calories (cal) to Megajoules (MJ) Conversion
Calories
The calorie (cal) is a unit of energy equal to exactly 4.184 joules, defined as the energy required to raise the temperature of one gram of water by one degree Celsius at 15 °C. This is the thermochemical calorie — distinct from the food calorie (written as Cal or kcal), which is 1,000 times larger. The calorie originated in 19th-century thermodynamics before the joule was established as the SI standard, and persists in chemistry, biology, and food science.
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.
| Calories (cal) | Megajoules (MJ) |
|---|---|
| 0.1 cal | 0.000000418 MJ |
| 1 cal | 0.00000418 MJ |
| 2 cal | 0.00000837 MJ |
| 3 cal | 0.0000126 MJ |
| 5 cal | 0.0000209 MJ |
| 10 cal | 0.0000418 MJ |
| 20 cal | 0.0000837 MJ |
| 30 cal | 0.000126 MJ |
| 50 cal | 0.000209 MJ |
| 100 cal | 0.000418 MJ |
| 1000 cal | 0.00418 MJ |
Frequently Asked Questions (FAQ)
How many megajoules are in 1 calories?
1 calories (cal) is exactly 0.00000418 megajoules (MJ).
How do I convert calories to megajoules?
Multiply the value in calories by 0.00000418 to get the result in megajoules. Or use the converter above — type any number and see the result instantly.