Convert darcy, millidarcy, m², ft², and more for reservoir engineering, groundwater studies, and porous media analysis. The converter updates instantly and covers both petroleum-friendly and SI-first workflows.
International System of Units (SI) measurements
Unit measurements
Traditional British and American measurements
Commonly used units in practical applications
Permeability describes how easily fluids move through porous rock, soil, filters, and other media. Engineers often work in darcy and millidarcy, while research papers and simulation models may use square meters. This page helps bridge those unit systems without manual math.
Use it for reservoir characterization, core plug analysis, groundwater flow, porous media experiments, and report preparation. If you also need fluid-property context, pair it with our Viscosity Converter, Flow Rate Converter, and Density Converter.
The standard petroleum conversion is based on the definition:1 darcy = 9.86923 × 10⁻¹³ m²
Common derived relationships:m² = darcy × 9.86923 × 10⁻¹³darcy = m² ÷ 9.86923 × 10⁻¹³mD = darcy × 1000
Unit conversion is exact, but real measured permeability still depends on rock structure, effective stress, fluid type, and test conditions.
Example
1 darcy = 9.86923 × 10⁻¹³ m²
Common SI reference conversion.
Example
100 mD = 0.1 darcy
Useful for formation permeability screening.
Example
250 mD = 2.46731 × 10⁻¹³ m²
Typical low-to-moderate reservoir rock value.
Example
5 × 10⁻¹³ m² = 0.5068 darcy
Reverse conversion for SI-first workflows.
Unit conversion does not replace engineering judgment. If you are comparing lab, field, and simulation values, make sure the reported permeability is absolute or effective as appropriate, and confirm the sample orientation and testing method.
Use the standard relationship 1 darcy = 9.86923 × 10⁻¹³ m². Enter the value in darcy, choose m² as the target unit, and the converter applies the factor instantly.
A millidarcy is one-thousandth of a darcy. This scale is common in reservoir engineering because many rock samples fall in the mD range rather than full darcy values.
Darcy and millidarcy are common in petroleum engineering and hydrogeology literature, while square meters are the SI unit used in scientific and standards-based calculations.
Unit conversions are exact for the measurement unit itself, but the measured permeability of a material still depends on sample conditions, anisotropy, temperature, and testing method.
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