Millijoule is 0.001 joule units.
Millijoules to Kilocalories Converter — mJ to kcal
Convert Millijoule (mJ) to Kilocalorie (kcal) using the exact conversion factor (1 millijoule = 2.390057e-7 kilocalorie). See the formula, worked examples, and conversion table.
Millijoules to Kilocalories converter
Converter
Engineering Converter
Convert common stress, force, torque, power, and energy units used in engineering.
Context values
Some unit families need one extra value for a physically accurate result.
A kilocalorie is 1,000 calories.
Result = input x 0.001 / 4184.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Millijoules to Kilocalories
Millijoule and Kilocalorie both measure a quantity used in structural or mechanical engineering — commonly stress, pressure, force, torque, power, or energy — where converting between the unit conventions used in different regions, industries, or equipment specifications is a routine part of design work. Specifically: Millijoule is 0.001 joule units, and a kilocalorie is 1,000 calories.
Formula
kilocalories = millijoules × 2.390057e-7
This factor comes from each unit's defined relationship to the category's base unit: 1 millijoule equals 0.001 base units, and 1 kilocalorie equals 4184 base units, so dividing one by the other gives the direct millijoule-to-kilocalorie factor of 2.390057e-7.
Simple example
1 mJ × 2.390057e-7 = 2.390057e-7 kcal
1 millijoule = 2.390057e-7 kilocalories.
Real-world example
100 mJ × 2.390057e-7 = 0.0000239006 kcal
100 millijoules = 0.0000239006 kilocalories.
Conversion table
| Millijoule (mJ) | Kilocalorie (kcal) |
|---|---|
| 1 mJ | 2.390057e-7 kcal |
| 10 mJ | 0.0000023901 kcal |
| 50 mJ | 0.0000119503 kcal |
| 100 mJ | 0.0000239006 kcal |
| 500 mJ | 0.0001195029 kcal |
| 1,000 mJ | 0.0002390057 kcal |
Reverse conversion: Kilocalorie to Millijoule
2.390057e-7 kcal × 4184000 = 0.9999998488 mJ
2.390057e-7 kilocalories = 0.9999998488 millijoules.
millijoules = kilocalories × 4184000
For a page dedicated to this direction, see Kilocalorie to Millijoule.
Understanding the Millijoule (mJ)
Millijoule is 0.001 joule units.
Understanding the Kilocalorie (kcal)
A kilocalorie is 1,000 calories.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many kilocalories are in 1 millijoule?
1 millijoule equals 2.390057e-7 kilocalories, using the exact defined conversion factor rather than an estimate.
How do I convert millijoule to kilocalorie?
Multiply the millijoule value by 2.390057e-7. The converter above does this instantly to whatever precision you set.
How do I convert kilocalorie back to millijoule?
Use the reverse factor: 1 kilocalorie equals 4,184,000 millijoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a millijoule?
Millijoule (mJ) is a unit of engineering.
What is a kilocalorie?
Kilocalorie (kcal) is a unit of engineering.
Is the millijoule to kilocalorie conversion exact?
Yes. Both millijoule and kilocalorie are defined by fixed standards rather than physical artifacts, so the factor of 2.390057e-7 used above is exact to as many digits as you choose to display.
Why do engineering unit conventions vary so much by region and industry?
Pressure, force, and stress can be expressed in metric (pascal, newton), US customary (psi, pound-force), or older and industry-specific units (atmosphere, torr, kip) depending on the country, industry, and even the equipment manufacturer, which is why engineers routinely need to convert between them when working across specs from different sources.