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Fluid Mechanics

Hazen-Williams Flow Rate Calculator

Calculate water flow rate in pressurised pipes using the Hazen-Williams equation given pipe diameter, hydraulic gradient, and C factor. Widely used by civil engineers for water main and irrigation system design.

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Fluid Mechanics

Manning's Roughness Flow Calculator

Estimate average flow velocity in an open channel or partially-full pipe using Manning's equation with hydraulic radius, slope, and roughness coefficient. Useful for stormwater design, culvert sizing, channel design, and natural-stream hydraulic analysis.

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Key differences

Hazen-Williams Flow Rate CalculatorManning's Roughness Flow Calculator
CategoryFluid MechanicsFluid Mechanics
Inputs required33
ResultFlow Rate (mΒ³/s)Flow Velocity (m/s)
What it doesCalculate water flow rate in pressurised pipes using the Hazen-Williams equation given pipe diameter, hydraulic gradient, and C factor. Widely used by civil engineers for water main and irrigation system design.Estimate average flow velocity in an open channel or partially-full pipe using Manning's equation with hydraulic radius, slope, and roughness coefficient. Useful for stormwater design, culvert sizing, channel design, and natural-stream hydraulic analysis.