Darcy-Weisbach Pressure Drop

Compute pipe pressure drop, head loss, and hydraulic power from flow rate and roughness.

visual calculatorInternal Flow & Losses

Read the flow shape before trusting the number.

This page turns a CFD setup into regime, scale, and dominant-effect cues. Adjust the calculator below and compare the moving graphic with the computed result.

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pipe flowpressure drophead lossDarcy-Weisbach

formula

KaTeX rendered

\begin{aligned}\text{Delta p = (f L/D + K) rho U\^{}2 / 2}\end{aligned}

ASCII source

Delta p = (f L/D + K) rho U^2 / 2

rho (kg/m^3)mu (Pa·s)Q (m^3/s)D (m)L (m)roughness epsilon (m)minor loss K

U (m/s)

2.5465

2.541e+5

Darcy f

0.01816

Delta p (Pa)

1.661e+4

head loss (m)

1.6968

hydraulic power (W)

332.1417

Pressure drop uses Delta p = (f L/D + K) rho U^2 / 2. Pump shaft power needs division by efficiency.

pipe flow pressure drop head loss Darcy-Weisbach