Laminar vs. Turbulent Flow - Reynolds Number Calculator

Calculate Reynolds Number to determine if flow is laminar, transient, or turbulent. The Reynolds Number is a dimensionless quantity that represents the ratio of inertial forces to viscous forces.

Calculator

Inputs

Density (ρ) (kg/m³)

Velocity (u) (m/s)

Characteristic Length (L) (m)

Dynamic Viscosity (μ) (Ns/m²)

Results

Reynolds Number (Re)--

Flow Type--

Calculator

Inputs

Velocity (u) (m/s)

Characteristic Length (L) (m)

Kinematic Viscosity (ν) (m²/s)

Results

Reynolds Number (Re)--

Flow Type--

Calculator

Inputs

Velocity (u) (ft/s)

Hydraulic Diameter (dh) (in)

Kinematic Viscosity (ν) (cSt)

Results

Reynolds Number (Re)--

Flow Type--

Regime	Reynolds Number Range	Description
Laminar	Re < 2300	Smooth, orderly flow with parallel layers
Transient	2300 < Re < 4000	Flow transitioning between laminar and turbulent
Turbulent	Re > 4000	Chaotic flow with irregular mixing