Reynolds Number Calculator
Laminar or turbulent flow test.
Enter your values
ⓘ Live results
Results
- Reynolds number
- 59,880
- Flow regime
- Turbulent
- Kinematic viscosity
- 0.000001 m²/s
- Velocity for Re = 2300
- 0.04609 m/s
Quick answer
The Reynolds number compares inertial to viscous forces; below 2300 flow is laminar, above 4000 turbulent.
Re = ρvD / μ
How to use the Reynolds Number Calculator
- 1Enter fluid density and viscosity.
- 2Enter flow velocity and pipe diameter in SI units.
- 3Read the regime classification.
Worked example
Using the values the calculator loads with:
Inputs
- Fluid density998 kg/m³
- Velocity1.2 m/s
- Pipe diameter0.05 m
- Dynamic viscosity0.001 Pa·s
Results
- Reynolds number59,880
- Flow regimeTurbulent
- Kinematic viscosity0.000001 m²/s
- Velocity for Re = 23000.04609 m/s
Frequently asked questions
Water at room temperature?
Density 998 kg/m³, viscosity about 0.001 Pa·s.
Why does the regime matter?
Turbulent flow mixes better but causes far higher pressure loss.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.