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Permeability

ft²tomD

Convert square feet (permeability) (ft²) to millidarcy (mD).

Factor1 ft² = 9.4134e+13 mD

Converter

ft²

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

Result
9.4134e+13mD

Rendered to 6 significant figures.

Formula

Formula
mD = ft² × 9.4134e+13

Multiply any value in square feet (permeability) by 9.4134e+13 to obtain the value in millidarcy.

Worked example

Convert 1 ft² to mD.

  1. 01Start with 1 ft².
  2. 02Multiply by the conversion factor: 1 × 9.4134e+13 = 9.4134e+13 mD.
Result1 ft² = 9.4134e+13 mD

Conversion table

ft²mD
19.4134e+13
21.8827e+14
54.7067e+14
109.4134e+14
201.8827e+15
504.7067e+15
1009.4134e+15
2001.8827e+16
5004.7067e+16
10009.4134e+16

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from ft² to mD?
1 ft² equals 9.4134e+13 mD. To convert, multiply the value in square feet (permeability) by 9.4134e+13.
How do I convert 1 ft² to mD?
1 ft² = 9.4134e+13 mD. For any value, multiply by 9.4134e+13.
How do I convert mD back to ft²?
Divide by the same factor — or equivalently, multiply by 1.062315e-14. So 1 mD = 1.06232e-14 ft².
When would I need to convert square foot (permeability) to millidarcy?
Permeability conversions between ft² 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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