Calories to Millijoules Converter
Enter the energy in calories below to convert it to millijoules.
Convert Calories to Millijoules
Enter a value in calories (cal) to convert to millijoules (mJ).
Gram Calorie to Millijoule Conversion Table
Table showing various gram calorie measurements converted to millijoules. Click any preset value or arrow to load it into the converter.
| Calories (cal) | Millijoules (mJ) |
|---|---|
| 1 cal | 4,184 mJ |
| 2 cal | 8,368 mJ |
| 2.5 cal | 10,460 mJ |
| 5 cal | 20,920 mJ |
| 10 cal | 41,840 mJ |
| 15 cal | 62,760 mJ |
| 20 cal | 83,680 mJ |
| 25 cal | 104,600 mJ |
| 30 cal | 125,520 mJ |
| 50 cal | 209,200 mJ |
How to Convert Calories to Millijoules
To convert calories to millijoules, multiply the energy by the following conversion ratio: 4,184 millijoules/gram calorie.
Since one gram calorie is equal to 4,184 millijoules, you can use this simple formula to convert:
The energy in millijoules is equal to the energy in calories multiplied by 4,184.
For example, here's how to convert 5 calories to millijoules using the formula above.
How Many Millijoules Are in a Gram Calorie?
There are 4,184 millijoules in a gram calorie, which is why we use this value in the formula above.
Our gram calorie to millijoule calculator automatically converts your energy measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Calories and millijoules are both units used to measure energy. Keep reading to learn more about each unit.
What Is a Gram Calorie?
A gram calorie is a unit of energy equal to 4.184 joules (J), the base unit for energy. Thermochemical gram calorie defined as 4.184 Joules. [1]
The gram calorie is classified as a standard unit of energy. Calories can be abbreviated as cal; for example, 1 gram calorie can be written as 1 cal.
When working with calories (cal) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, calories (cal) are widely used across standard energy applications within international standard workflows, engineering documentation, and technical data sheets.
What Is a Millijoule?
A millijoule is a unit of energy equal to 1/1,000 of a joule (0.001 J). One-thousandth of a Joule. [2]
The millijoule is classified as a metric and SI-compatible unit of energy. Millijoules can be abbreviated as mJ; for example, 1 millijoule can be written as 1 mJ.
In the metric system, "milli" is the standard SI prefix for thousandths, or 10⁻³. This makes the millijoule (mJ) a convenient decimal multiple of the joule (J).
In practice, millijoules (mJ) are widely used across fine-tolerance laboratory, analytical, and micro-scale energy measurements within SI metric workflows, engineering documentation, and technical data sheets.
When converting energy between calories (cal) and millijoules (mJ), keep full floating-point precision (1 cal = 4,184 mJ; 1 mJ = 0.000239006 cal) during intermediate calculations and round only the final millijoule figure to match your instrument tolerance.
More Gram Calorie & Millijoule Conversions
Need to calculate in the opposite direction? Use our millijoules to calories calculator to switch your starting unit immediately. You can also explore related tools such as converting millijoules to calories, converting calories to joules, or converting calories to kilocalories.
Convert from Calories
Frequently Asked Questions
References
- [1]NIST CODATA StandardNIST CODATA (CODATA Energy & Thermodynamic Constants)·Energy Metrology Standard — Calories (cal) to Millijoules (mJ)
- [2]NIST SP 811 SpecificationNIST SP 811 (NIST SP 811 App. B.9 (Energy, Work & Heat))·Unit Specifications: Gram Calorie (cal) (cal) & Millijoule (mJ)
- [3]BIPM ReferenceBIPM (Derived SI Unit: Joule (J))·Conversion Factors & Mathematical Basis (cal to mJ)