Drainage
Calculate Drainage instantly with the exact formula and a worked example.
Drainage
House lengthm
House widthm
Drain offset from wallm
Pipe slopemm/m
Drain length
44m
Length of one branch to the sump
22m
Drop per branch
6.6cm
More about: Drainage
What it calculates
The “Drainage” calculator computes Drain length in m from 4 parameters: house length (m), house width (m), drain offset from wall (m), pipe slope (mm/m).
Used in design, material estimation, and structural calculations.
Example calculation
With parameters House length = 10 m, House width = 8 m, Drain offset from wall = 1 m, Pipe slope = 3 mm/m the result is 44 m (Minimum slope: 2 mm/m in clay, 3 mm/m in sandy soils).
How to use
- Enter house length, house width, drain offset from wall and pipe slope — each field above is adjustable with a slider.
- Drain length (m) is calculated automatically as you type.
- Check the worked example below to see the formula applied to real numbers.
- Copy the result or bookmark this calculator.
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FAQ
How is Drainage calculated?
The Drainage calculator computes Drain length (in m) from house length, house width, drain offset from wall, pipe slope. Enter your values above and the exact formula is applied instantly; a worked example with real numbers is shown below.
Is the Drainage calculator free?
Yes. It is completely free, needs no signup, runs entirely in your browser, and sends no data to any server.
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