Pipe Friction Loss Calculator

Calculate pressure drop, head loss, velocity, friction factor, and Reynolds number for fluid flow in a single pipe. Choose between the Darcy-Weisbach equation with Colebrook-White roughness (the rigorous standard for any fluid and flow regime) or the Hazen-Williams empirical formula (water-only, turbulent flow). Inputs: flow rate or velocity, pipe diameter, length, roughness or C-coefficient, and fluid density and viscosity.

Results display in SI or imperial units. The Colebrook-White solution iterates internally for the Darcy friction factor. Reynolds number is shown so you can verify flow regime (laminar < 2300, transitional, turbulent > 4000).

Related calculators: pipe sizing, Reynolds number, valve sizing. For multi-pipe networks, build a model in SimuPipe.