Pipe Flow & Pressure Drop Calculator

Calculate liquid velocity, Reynolds number, Darcy friction factor, pressure drop and head loss using Darcy–Weisbach with a Swamee–Jain turbulent-flow approximation.

Flow rate

m³/h

Internal diameter

Pipe length

Absolute roughness

Fluid density

kg/m³

Dynamic viscosity

Pa·s

Minor-loss coefficient ΣK

Velocity

2.829 m/s

Reynolds number

141188

Turbulent

Darcy friction factor

0.0213

Pressure drop

190.30 kPa

Head loss

19.44 m

Equations used

ΔP = [f(L/D) + ΣK]·ρv²/2. For Re < 2300, f = 64/Re. For turbulent flow, this tool uses the explicit Swamee–Jain approximation. Verify actual internal diameter, roughness, temperature-dependent properties, valves/fittings and elevation separately for final pump/system design.