Friction Loss Calculator

Calculate pipe friction loss using Hazen-Williams

Flow Parameters

Fitting Equivalent Lengths

Friction Loss Results

Total Head Loss --
Pressure Drop --
Loss per 100 ft --
Pipe Loss --
Fitting Loss --
Flow Velocity --

Equivalent Length Reference

Fitting 1/2" 3/4" 1" 1-1/2" 2"
90 Elbow1.522.545
45 Elbow0.811.222.5
Tee (Branch)345810
Gate Valve0.30.40.50.81
Ball Valve0.30.40.50.81
Values in feet of equivalent pipe length

Friction Loss Table (PSI per 100 ft)

GPM 1/2" 3/4" 1" 1-1/4" 1-1/2" 2"
Table generated for selected pipe material (C=130)

Hazen-Williams Formula

hf = 10.67 x L x Q1.85 / (C1.85 x D4.87)

hf = Head loss (ft)

L = Length (ft)

Q = Flow (cfs)

C = Roughness coefficient

D = Diameter (ft)

PSI = hf x 0.433