Attojoules to Millijoules Converter
Enter the energy in attojoules below to convert it to millijoules.
Convert Attojoules to Millijoules
Enter a value in attojoules (aJ) to convert to millijoules (mJ).
Attojoule to Millijoule Conversion Table
Table showing various attojoule measurements converted to millijoules. Click any preset value or arrow to load it into the converter.
| Attojoules (aJ) | Millijoules (mJ) |
|---|---|
| 1 aJ | 1e-15 mJ |
| 10 aJ | 1e-14 mJ |
| 100 aJ | 1e-13 mJ |
| 1,000 aJ | 1e-12 mJ |
| 10,000 aJ | 1e-11 mJ |
| 100,000 aJ | 1e-10 mJ |
| 1,000,000 aJ | 1e-9 mJ |
| 5,000,000 aJ | 5e-9 mJ |
| 10,000,000 aJ | 0.00000001 mJ |
| 25,400,000 aJ | 0.000000025 mJ |
How to Convert Attojoules to Millijoules
To convert attojoules to millijoules, multiply the energy by the following conversion ratio: 1e-15 millijoules/attojoule.
Since one attojoule is equal to 1e-15 millijoules, you can use this simple formula to convert:
The energy in millijoules is equal to the energy in attojoules multiplied by 1e-15.
For example, here's how to convert 5 attojoules to millijoules using the formula above.
How Many Millijoules Are in an Attojoule?
There are 1e-15 millijoules in an attojoule, which is why we use this value in the formula above.
Our attojoule to millijoule calculator automatically converts your energy measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Attojoules and millijoules are both units used to measure energy. Keep reading to learn more about each unit.
What Is an Attojoule?
An attojoule is a unit of energy equal to 1/999,999,999,999,999,900 of a joule (1e-18 J). 10⁻¹⁸ Joules. [1]
The attojoule is classified as a metric and SI-compatible unit of energy. Attojoules can be abbreviated as aJ; for example, 1 attojoule can be written as 1 aJ.
When working with attojoules (aJ) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, attojoules (aJ) are widely used across fine-tolerance laboratory, analytical, and micro-scale energy measurements within SI metric 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 attojoules (aJ) and millijoules (mJ), keep full floating-point precision (1 aJ = 1e-15 mJ; 1 mJ = 1e+15 aJ) during intermediate calculations and round only the final millijoule figure to match your instrument tolerance.
More Attojoule & Millijoule Conversions
Need to calculate in the opposite direction? Use our millijoules to attojoules calculator to switch your starting unit immediately. You can also explore related tools such as converting millijoules to attojoules, converting joules to calories, or converting calories to joules.
Convert from Attojoules
Frequently Asked Questions
References
- [1]NIST CODATA StandardNIST CODATA (CODATA Energy & Thermodynamic Constants)·Energy Metrology Standard — Attojoules (aJ) to Millijoules (mJ)
- [2]NIST SP 811 SpecificationNIST SP 811 (NIST SP 811 App. B.9 (Energy, Work & Heat))·Unit Specifications: Attojoule (aJ) & Millijoule (mJ)
- [3]BIPM ReferenceBIPM (Derived SI Unit: Joule (J))·Conversion Factors & Mathematical Basis (aJ to mJ)