Pipe Pressure Drop Calculator

📈 Pipe Pressure Drop Calculator

Darcy-Weisbach equation — for liquids in circular pipes

Pipe Length (ft)

Inner Diameter (in)

Flow Rate (GPM)

Kinematic Viscosity (cSt)

Fluid Density (lb/gal)

Pipe Material / Roughness

Pressure Drop

—

psi

Flow Velocity

—

ft/s

Reynolds Number

—

dimensionless

Darcy Friction Factor

—

ΔP = f × (L/D) × (ρv²/2)

Turbulent friction factor (Swamee-Jain): f = 0.25 / [log₁₀(ε/3.7D + 5.74/Re⁰⋅⁹)]²

Laminar (Re < 2300): f = 64 / Re