Pressure Loss Calculator

Calculate friction loss in water supply piping using Hazen-Williams.

Flow Conditions

Pipe Details

Fittings (Optional)

Hazen-Williams Formula

h = 10.67 × L × Q1.852 / (C1.852 × D4.87)

h = head loss (ft), L = length (ft), Q = flow (GPM), C = roughness coefficient, D = diameter (in)

Hazen-Williams C Values

MaterialC Value
Copper, PEX, CPVC150
New Steel/Iron140
Cast Iron (new)130
Cast Iron (20 years)100
Corroded/Tuberculated80