This app provides a quick and easy way to calculate Reynolds Number. The user only needs to enter in the fluid properties, characteristic length, and fluid velocity. Density and dynamic viscosity calculators are given for air and water. A hydraulic diameter calculator is also included for problems involving internal flow in rectangular ducts.

What is Reynolds Number?
The Reynolds number is a dimensionless number used to describe flow conditions in Newtonian Fluids. It is a ratio of inertial forces to viscous forces in the fluid. If the flow is internal, the Reynolds Number can tell you if the fluid flow is Turbulent, Laminar, or Transitional. This number is commonly used in a variety of engineering scenarios.

Currently Supported Units
Density: kg/m^3, lbm/ft^3, lbm/in^3
Dynamic Viscosity: Pa*s (kg/m-s), centipoise, lbm/s-ft
Length/Diameter: m, cm, ft, in
Fluid Velocity: m/s, cm/s, ft/s, in/s