Reynolds Number Calculator

Calculate Reynolds number to determine flow regime (laminar, transitional, or turbulent)

Input Parameters

1000 kg/m³ for pure water
1.0 cP at 20°C

Results

Enter values and click "Calculate Reynolds Number" to see results.

How to Use

Enter the pipe diameter, flow velocity, water density, and dynamic viscosity. The calculator will determine the Reynolds number and classify the flow regime.

Reynolds Number: Re = (ρ × v × D) / μ
Where:
ρ = Fluid density (kg/m³)
v = Flow velocity (m/s)
D = Characteristic diameter (m)
μ = Dynamic viscosity (Pa·s)

Flow Regimes:
Re < 2300: Laminar flow
2300 ≤ Re ≤ 4000: Transitional flow
Re > 4000: Turbulent flow