Pipe Friction Loss

Estimate pressure drop in water pipes with the Hazen-Williams equation — before you buy the pump.

Flow rate (GPM)

Pipe inside diameter (inches)

Pipe length (feet)

Pipe material (C factor)

Hazen-Williams
h_f (ft / 100 ft) = 0.2083 × (100/C)^1.852 × Q^1.852 ÷ d^4.8655

Then psi = head ÷ 2.31. Result is an estimate for clean water — fittings and temperature change real-world values.

🛠 Pump sizing

Know the pressure your pump must overcome.

🔬 Material factors

C values for PVC, copper, steel and more.

🚁 Velocity check

Warns on noisy or damaging flow speeds.

🏟 Whole-run totals

Scales loss by your actual pipe length.

More flow & plumbing tools

Design piping with confidence.

Duct Size → Conduit Size Water Tank