Darcy–Weisbach Calculator
Calculate head loss hf (m) from friction factor, length, diameter, and velocity.
Formula
hf = f · (L/D) · (v² / 2g)
Friction factor f may be from Moody chart, Colebrook, or explicit correlations depending on regime.
Frequently Asked Questions
Laminar vs turbulent?
For laminar flow, f = 64/Re. For turbulent flow, use Colebrook or explicit approximations.
Minor losses?
Elbows, valves, and fittings add K v²/(2g). This calculator covers major (friction) loss only.