Hazen-Williams Pipe Friction Calculator

Calculate pressure loss in water pipes using the Hazen-Williams equation for smooth-bore pipe flow.

Water flow rate through the pipe.
GPM
Internal diameter of the pipe.
inches
Total length of pipe run.
feet
Roughness coefficient: 150 (copper/PEX), 140 (new steel), 120 (old steel), 100 (old iron).

Results

Head Loss-feet
Pressure Loss-PSI
Velocity-ft/s
References: Based on Hazen-Williams formula per ASPE Data Book Ch. 4