Darcies to Millidarcies Converter
Enter the permeability in darcies below to convert it to millidarcies.
Convert Darcies to Millidarcies
Enter a value in darcies (D) to convert to millidarcies (mD).
Darcy to Millidarcy Conversion Table
Table showing various darcy measurements converted to millidarcies. Click any preset value or arrow to load it into the converter.
How to Convert Darcies to Millidarcies
To convert darcies to millidarcies, multiply the permeability by the following conversion ratio: 1,000 millidarcies/darcy.
Since one darcy is equal to 1,000 millidarcies, you can use this simple formula to convert:
The permeability in millidarcies is equal to the permeability in darcies multiplied by 1,000.
For example, here's how to convert 5 darcies to millidarcies using the formula above.
How Many Millidarcies Are in a Darcy?
There are 1,000 millidarcies in a darcy, which is why we use this value in the formula above.
Our darcy to millidarcy calculator automatically converts your permeability measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Darcies and millidarcies are both units used to measure permeability. Keep reading to learn more about each unit.
What Is a Darcy?
A darcy is a unit of permeability equal to 9.869233e-13 square meters (m²), the base unit for permeability. Petroleum reservoir permeability unit (≈ 0.986923 µm²). [1]
The darcy is classified as a standard unit of permeability. Darcies can be abbreviated as D; for example, 1 darcy can be written as 1 D.
When working with darcies (D) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, darcies (D) are widely used across fine-tolerance laboratory, analytical, and micro-scale permeability measurements within international standard workflows, engineering documentation, and technical data sheets.
What Is a Millidarcy?
A millidarcy is a unit of permeability equal to 9.869233e-16 square meters (m²), the base unit for permeability. One-thousandth of a Darcy (9.869×10⁻¹⁶ m²). [2]
The millidarcy is classified as a standard unit of permeability. Millidarcies can be abbreviated as mD; for example, 1 millidarcy can be written as 1 mD.
In the metric system, "milli" is the standard SI prefix for thousandths, or 10⁻³. This makes the millidarcy (mD) a convenient decimal multiple of the square meter (m²).
In practice, millidarcies (mD) are widely used across fine-tolerance laboratory, analytical, and micro-scale permeability measurements within international standard workflows, engineering documentation, and technical data sheets.
When converting permeability between darcies (D) and millidarcies (mD), keep full floating-point precision (1 D = 1,000 mD; 1 mD = 0.001 D) during intermediate calculations and round only the final millidarcy figure to match your instrument tolerance.
More Darcy & Millidarcy Conversions
Need to calculate in the opposite direction? Use our millidarcies to darcies calculator to switch your starting unit immediately. You can also explore related tools such as converting millidarcies to darcies, converting square meters (m²) to millidarcies, or converting darcies to square meters (m²).
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Frequently Asked Questions
References
- [1]NIST OWM StandardNIST OWM (SI Units — Length)·Permeability Metrology Standard — Darcies (D) to Millidarcies (mD)
- [2]BIPM SpecificationBIPM (SI Base Unit: Metre (m))·Unit Specifications: Darcy (D) & Millidarcy (mD)
- [3]NIST HB 133 ReferenceNIST HB 133 (NIST Handbook 133 (2019 Ed.))·Conversion Factors & Mathematical Basis (D to mD)