How do I calculate Reynolds Number & Flow Regime?

To calculate Reynolds Number & Flow Regime: Enter Pipe internal diameter D, Flow velocity v, Fluid and other values. Click Calculate. INDUGRID computes the result instantly using the formula: Re = ρ × v × D / η = v × D / ν | f_laminar = 64/Re | f_turbulent = 0.316/Re^0.25 (Blasius). No registration required.

What units does the Reynolds Number & Flow Regime calculator use?

The Reynolds Number & Flow Regime calculator uses the following units: mm, m/s, m. SI units are used by default.

Is the Reynolds Number & Flow Regime calculator free?

Yes. The INDUGRID Reynolds Number & Flow Regime calculator is completely free, requires no account or login, and works on desktop and mobile browsers.

Fluid Mechanics

Reynolds Number & Flow Regime

Calculate Reynolds number and determine whether flow is laminar or turbulent, with friction factor for Darcy-Weisbach pressure drop calculation.

Units:

in LinkedIn

💡Re < 2300: laminar (smooth, predictable). Re > 4000: turbulent (higher losses, better mixing). Transitional zone 2300–4000 is unstable. In hydraulic lines, turbulent flow is normal and expected. In lubrication systems, laminar flow is preferred.

Re = ρ × v × D / η = v × D / ν | f_laminar = 64/Re | f_turbulent = 0.316/Re^0.25 (Blasius)

Input

Pipe internal diameter D iInternal diameter of the pipe or channel in mm.

Flow velocity v iMean flow velocity in m/s.

m/s

Fluid iSelect the fluid. Dynamic viscosity and density are automatically applied.

Pipe length L iPipe length in metres for pressure drop calculation.

Result

Reynolds number Re —

Flow regime —

Darcy friction factor f —

Pressure drop ΔP [bar] —

Pressure drop ΔP [kPa] —