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Permeability

µm²tomD

Convert square micrometres (permeability) (µm²) to millidarcy (mD).

Factor1 µm² = 1013.25 mD

Converter

µm²

Accepts numbers or expressions, e.g. 150 + 14.7

Result
1013.25mD

Rendered to 6 significant figures.

Formula

Formula
mD = µm² × 1013.25

Multiply any value in square micrometres (permeability) by 1013.25 to obtain the value in millidarcy.

Worked example

Convert 1 µm² to mD.

  1. 01Start with 1 µm².
  2. 02Multiply by the conversion factor: 1 × 1013.25 = 1013.25 mD.
Result1 µm² = 1013.25 mD

Conversion table

µm²mD
11013.2
22026.5
55066.2
1010132
2020265
5050662
1001.0132e+5
2002.0265e+5
5005.0662e+5
10001.0132e+6

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from µm² to mD?
1 µm² equals 1013.25 mD. To convert, multiply the value in square micrometres (permeability) by 1013.25.
How do I convert 1 µm² to mD?
1 µm² = 1013.25 mD. For any value, multiply by 1013.25.
How do I convert mD back to µm²?
Divide by the same factor — or equivalently, multiply by 0.0009869233. So 1 mD = 0.000986923 µm².
When would I need to convert square micrometre (permeability) to millidarcy?
Permeability conversions between µm² and mD appear in petroleum and reservoir engineering, hydrogeology, geotechnical engineering, packed-bed filtration and porous-materials research. The darcy (D) and its sub-multiples (mD, µD, nD) dominate petroleum-engineering documentation; SI area-equivalent units (m², µm², mm², cm², ft²) appear in geophysics and porous-media research. Intrinsic permeability is a property of the porous medium alone — this category does NOT include hydraulic conductivity (m/s, requires fluid density and viscosity), gas permeability (Klinkenberg slip corrections) or membrane-permeability coefficients, all of which are different physical quantities and require explicit assumptions.
Is the conversion exact?
The factor shown is precise to at least 7 significant figures. For most process-engineering work this is far better than instrument accuracy. For metrology or trade applications, refer to the relevant national standard (NIST, BIPM, ISO 80000).

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