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Hydraulic Conductivity Calculator.

Calculate Darcy hydraulic conductivity from a measured flow experiment.

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Hydraulic conductivity: 0.002

Hydraulic conductivity

0.000000

Educational SI models with assumptions stated in each description; verify engineering decisions independently.

Use Cases

Laboratory Permeability Testing

Determine the hydraulic conductivity of soil or rock samples in a lab by measuring flow rate, sample dimensions, and head difference.

Example: A soil sample with length 0.1 m, area 0.005 m², flow rate 1e-6 m³/s, and head difference 0.5 m yields K = 4e-5 m/s.

Groundwater Flow Analysis

Estimate the ease with which groundwater moves through an aquifer, helping hydrogeologists assess water supply and contamination spread.

Example: Using field measurements, calculate K to evaluate aquifer productivity.

Frequently Asked Questions

What is hydraulic conductivity?
Hydraulic conductivity (K) measures how easily a fluid can move through a porous medium. It is calculated using Darcy's law: K = (flow rate × sample length) / (cross-sectional area × head difference). The result is in meters per second (m/s).
What units does this calculator use?
All inputs must be in SI units: flow rate in cubic meters per second (m³/s), sample length in meters (m), cross-sectional area in square meters (m²), and head difference in meters (m). The output is hydraulic conductivity in meters per second (m/s).
Can I use this calculator for any fluid?
This calculator is based on Darcy's law for fluid flow through porous media. It assumes the fluid is incompressible and the flow is laminar. It is typically used for water, but can be used for other fluids if the flow conditions meet Darcy's assumptions.

Tips & Common Mistakes

Tips

  • Ensure all inputs are in consistent SI units (m³/s, m, m², m) to get the correct result in m/s.
  • Measure the cross-sectional area perpendicular to the flow direction, not the surface area of the sample.
  • Use the head difference (Δh) between the inlet and outlet, not the total pressure.
  • For accurate results, perform multiple flow rate measurements and use the average.

Common Mistakes to Avoid

  • Using inconsistent units, such as cm for length and m² for area, which leads to incorrect results.
  • Confusing head difference with total head or pressure, which can skew the calculation.
  • Neglecting to account for the actual cross-sectional area of the sample, especially if it is not uniform.

Last updated: August 13, 2026