Engineering tool · SI units

Pipe friction & head loss calculator

Estimate pipe friction, fitting losses, elevation head and the total head your pump must overcome. Results update as you change the inputs.

MethodDarcy–WeisbachColebrook–White for turbulent flow

Fluid & operating condition

Water properties are calculated from temperature.

Fluid Temperature

°C

Water at 20°C · ρ = 998.2 kg/m³ · μ = 1.002 mPa·s

Pipe parameters

Use the actual internal diameter, not nominal outside size.

Pipe material Absolute roughness ε

Internal diameter D

Straight pipe length L

Flow & elevation

Enter a design flow or calculate from a known velocity.

Calculate by flow Calculate by velocity

Volumetric flow Q

Elevation difference Δz

Outlet minus inlet; negative values reduce required head.

Fittings & valves

Minor losses use hₘ = ΣK·v²/(2g).

ΣK = 5.75

System characteristic

How loss changes with flow.

Indicative curve based on current pipe, fluid, fittings and elevation inputs. Use the confirmed operating point when matching a pump curve.

Calculation basis

Transparent formulas, practical limits.

This tool is intended for preliminary pump and piping estimates. Confirm the final system with project-specific data and applicable engineering standards.

Pipe frictionh_f = λ · L/D · v²/(2g)

Darcy–Weisbach equation.

Minor lossh_m = ΣK · v²/(2g)

Fitting and valve loss coefficients.

Total headΔH = h_f + h_m + Δz

Friction, fittings and elevation.

Flow regimeRe = ρvD/μ

64/Re for laminar flow; Colebrook–White for turbulent flow.

Assumptions

Single-phase, steady, fully developed flow in a circular pipe. Air calculations are suitable only where density change is small; use a compressible-flow method for material gas pressure drop. K values are typical reference values and should be replaced by manufacturer or project data when available.