JavaScript is off. Reference tables, cheat sheets and guides below are fully readable. The calculators, search and navigation need JavaScript — everything still runs in your browser, nothing is sent anywhere. Browse all tools

Pipe Pressure Drop

Darcy-Weisbach: Δp = f·(L/D)·(ρv²/2). Friction factor is 64/Re when laminar (Re < 2300), otherwise the Swamee-Jain explicit fit to Colebrook. Straight pipe only — add fittings as equivalent length.

Calculator

Inside Ø (mm)

Flow (L/min)

Length (m)

Density ρ (kg/m³)

Viscosity µ (Pa·s)

Roughness ε (mm)

Fittings ΣK

—

Velocity

—

Reynolds

—

Regime

—

Friction Δp

—

Fittings Δp

—

Head loss

—

Tap a fitting to add its K — they are additive, and on a short run they usually beat the straight pipe. Fluid properties and wall roughness come from the two pickers above.

Straight-pipe, steady, incompressible flow. A helper, not a substitute for engineering judgment.