🛢️ Friction Factor Calculator
Calculate the Darcy friction factor for flow in a pipe, used to estimate frictional pressure losses.
What This Calculates
The Darcy friction factor quantifies frictional energy loss for fluid flowing through a pipe, a core parameter in the Darcy-Weisbach pressure drop equation used in plumbing and pipeline design.
The Formula
For laminar flow (Re < 2300): f = 64/Re. For turbulent flow, this calculator uses the Swamee-Jain approximation to the Colebrook-White equation: f = 0.25 / [log₁₀(ε/(3.7D) + 5.74/Re^0.9)]², where ε/D is the pipe’s relative roughness.
For general educational and planning purposes.
Last reviewed August 2026