Moody Diagram — Pipe Flow Friction Factor

Relative Roughness ε/D:

The Moody diagram displays the Darcy-Weisbach friction factor f vs Reynolds number Re. Laminar: f=64/Re. Turbulent smooth: Prandtl/Colebrook-White. Fully rough: f=1/(2log(3.7D/ε))². Move cursor over the diagram to read off values.