Reynolds Number Calculator
Use this calculator to determine the Reynolds number, a dimensionless quantity used to predict flow patterns in different fluid flow situations.
What this calculator is doing
The Reynolds number is a fundamental dimensionless value in fluid mechanics that indicates whether flow is laminar, transitional, or turbulent.
It is calculated by:
\[ Re = \frac{\rho v L}{\mu} \]
Or using kinematic viscosity \( \nu = \mu / \rho \):
\[ Re = \frac{v L}{\nu} \]
Where:
\( Re \) = Reynolds number (dimensionless)
\( \rho \) = Fluid density (kg/m³)
\( v \) = Flow velocity (m/s)
\( L \) = Characteristic length (m)
\( \mu \) = Dynamic viscosity (Pa·s or N·s/m²)
\( \nu \) = Kinematic viscosity (m²/s)
Flow regimes:
- \( Re < 2300 \): Laminar
- \( 2300 \le Re \le 4000 \): Transitional
- \( Re > 4000 \): Turbulent
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Disclaimer: These calculators are provided for informational purposes only. Always verify your designs against relevant engineering standards and consult a qualified professional. We do not take responsibility for any errors or damages resulting from the use of these calculations.