What this converter does
This converter changes hydraulic conductivity between m/s, cm/s, m/day, ft/day and darcy. Lab reports, groundwater models and US practice all use different units for the same soil property. Every pair uses an exact factor, so results stay precise. Type a value and read the answer instantly.
Soil permeability spans a huge range — from about 1e-2 m/s in clean gravel down to 1e-9 m/s in clay.
The units it covers
Hydraulic conductivity units, each expressed against the metre per second.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Metre per second | m/s | 1 | SI, soil mechanics |
| Centimetre per second | cm/s | 0.01 | Lab test reporting |
| Metre per day | m/day | 1.1574e-5 | Groundwater flow |
| Foot per day | ft/day | 3.5278e-6 | US hydrogeology |
| Darcy | darcy | 9.6699e-6 | Petroleum, ≈ water at 20°C |
The formula
Each unit has a fixed value in m/s, so any pair converts through m/s:
result = value × factor_from ÷ factor_toWhere:
- value = the number you typed
- factor_from = the “from” unit in m/s
- factor_to = the “to” unit in m/s
Worked example
Convert 1×10⁻⁵ m/s to feet per day.
1 ft/day = 3.5278e-6 m/s1e-5 ÷ 3.5278e-6 = 2.835 ft/daySo 1×10⁻⁵ m/s is about 2.83 ft/day — a moderately permeable silty sand.
The units in this example
The SI unit of hydraulic conductivity used in soil mechanics and seepage analysis.
- 1 m/s = 100 cm/s
- 1 m/s ≈ 283,465 ft/day
- 1 m/s = 86,400 m/day
- gravel ≈ 1e-2 m/s
A US hydrogeology unit for groundwater flow and aquifer permeability.
- 1 ft/day = 3.528e-6 m/s
- 1 ft/day ≈ 0.305 m/day
- sand ≈ 5–500 ft/day
- clay < 0.01 ft/day