Reynolds Number Calculator
Free calculate re = ρvd/μ for fluid flow. determine flow regime (laminar, transitional, turbulent) from reynolds number.
Input Parameters
kg/m³
Pa·s
Diameter for pipe flow, chord for airfoil
Results
Enter parameters to calculate Reynolds number
Reynolds Number Formula
Formula
Re = ρvD / μ
Where:
- • Re = Reynolds number (dimensionless)
- • ρ = density (kg/m³)
- • v = velocity (m/s)
- • D = characteristic length (m)
- • μ = dynamic viscosity (Pa·s)
Flow Regimes
- • Laminar: Re < 2300
- • Transitional: 2300 ≤ Re < 4000
- • Turbulent: Re ≥ 4000