Reynolds Number Calculator

Calculate the Reynolds number and determine the flow regime (laminar, transitional, or turbulent).

Fluid Velocity (m/s)

Characteristic Length (m)

Kinematic Viscosity (m²/s)

Fluid Preset

Reynolds Number

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Flow Regime

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Inertial Force

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Viscous Force

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Dynamic Viscosity (approx)

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Reynolds Number Formula

Re = V × L / ν

Laminar: Re < 2,300

Transitional: 2,300 ≤ Re ≤ 4,000

Turbulent: Re > 4,000

The Reynolds number is a dimensionless quantity used to predict flow patterns. It compares inertial forces to viscous forces within a fluid.

Flow rate & pressure drop.

Pressure & velocity.

Kinematics.

Material mechanics.

Gear design.

Convert units.