How to Convert Megajoules to Calories (MJ to cal)
Energy conversions link food labels in kJ and kcal, SP Group bills in kWh and air-conditioner capacity in BTU. This guide shows how to convert megajoules into calories by hand, with examples and a quick-reference table.
The conversion
To convert megajoules to calories, multiply the value by 239,005.7361376673. To go the other way, divide by the same number (or multiply by 4.184000e-06). For a quick estimate, multiply by about 240,000.
Calories = megajoules × 239,005.7361376673
Worked examples
- 3 MJ = 717,017.21 cal
- 12.5 MJ = 2,987,571.7 cal
- 75 MJ = 17,925,430.21 cal
Megajoules to Calories table
| Megajoules | Calories |
|---|---|
| 1 MJ | 239,005.74 cal |
| 2 MJ | 478,011.47 cal |
| 5 MJ | 1,195,028.68 cal |
| 10 MJ | 2,390,057.36 cal |
| 20 MJ | 4,780,114.72 cal |
| 25 MJ | 5,975,143.4 cal |
| 50 MJ | 11,950,286.81 cal |
| 100 MJ | 23,900,573.61 cal |
| 250 MJ | 59,751,434.03 cal |
| 500 MJ | 119,502,868.07 cal |
| 1,000 MJ | 239,005,736.14 cal |
Common questions
Is MJ to cal exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Calories to Megajoules converter.
Mistakes to avoid
Dropping the units
A bare number without a unit is easy to misread later. Always write the unit with the result.
Rounding the factor too early
Using 3 instead of 3.28 for feet per metre introduces an error of almost 9% before you have started.
Multiplying when you should divide
Converting to a smaller unit gives a bigger number, and converting to a larger unit gives a smaller one. If your answer moves the wrong way, you have inverted the factor.
Background
Writing the units next to every number while you work is the simplest way to avoid mistakes. If the units do not cancel to leave the one you want, the calculation is set up wrongly.
Many conversion factors are exact by definition. The inch has been defined as exactly 2.54 centimetres since 1959, and the pound as exactly 0.45359237 kilograms, so conversions involving them can be as precise as you need.
Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.
For any value, use the Megajoules to Calories Converter or browse all energy converters.
Run your own numbers: Megajoules to Calories Converter