EVERYDAY CLARITY
Physics Reynolds Number Calculator
What Reynolds number describes this fluid flow? Enter the stated inputs to calculate this model.
Your result
Reynolds number
1
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Density (kg/m³) | Enter density in kg/m³; use the same basis as the other measurements. |
| Mean speed (m/s) | Enter mean speed in m/s; use the same basis as the other measurements. |
| Characteristic length (m) | Enter characteristic length in m; use the same basis as the other measurements. |
| Dynamic viscosity (Pa·s) | Enter dynamic viscosity in Pa·s; use the same basis as the other measurements. |
Understanding your result
Read Reynolds number (1) in the units and model stated on this page. The formula reynolds=rho*velocity*diameter/mu defines the relationship; measurement accuracy and model applicability are separate from numerical precision.
Common mistakes
- Mixing input units or changing the physical meaning of a variable without changing the model.
Check your calculation
- Use the worked example as a known reference case, then change one input at a time and check the direction and units of the response.
Calculation checks, sources and review limits
What Reynolds number describes this fluid flow?
What Reynolds number describes this fluid flow? Enter the stated inputs to calculate this model.
Common uses
- What Reynolds number describes this fluid flow
How it works
reynolds=rho*velocity*diameter/mu
Worked example
Enter Density: 1000 kg/m³; Mean speed: 1 m/s; Characteristic length: 0.01 m; Dynamic viscosity: 0.001 Pa·s. Results: Reynolds number: 10000 1.