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Storm Water Drainage Calculator

Estimate peak stormwater runoff and determine the minimum pipe diameter needed to handle it. Used by civil engineers and drainage designers when sizing pipes for subdivisions, roads, or urban catchments.

Catchment Area (hectares)

Design Rainfall Intensity (mm/hr)

Runoff Coefficient

Pipe Slope (%)

Manning's Roughness Coefficient

Fill in the required fields to see your result.

Civil

Earthwork Cut & Fill Calculator

Calculate the volume of soil to cut or fill when grading a site from an existing elevation to a target finish grade. Used by contractors and civil engineers for site grading, road construction, and land development projects.

Project Area (sq ft)

Existing Grade (ft elevation)

Finish Grade (ft elevation)

Fill in the required fields to see your result.

Key differences

	Storm Water Drainage Calculator	Earthwork Cut & Fill Calculator
Category	Civil	Civil
Inputs required	5	3
Result	Required Pipe Diameter (mm)	Material Volume (cubic yards)
What it does	Estimate peak stormwater runoff and determine the minimum pipe diameter needed to handle it. Used by civil engineers and drainage designers when sizing pipes for subdivisions, roads, or urban catchments.	Calculate the volume of soil to cut or fill when grading a site from an existing elevation to a target finish grade. Used by contractors and civil engineers for site grading, road construction, and land development projects.