Reynolds Number Calculator

🌊 Reynolds Number Calculator

Determine flow regime: laminar, transitional, or turbulent

Quick Fluid Presets

Flow Velocity (ft/s)

Pipe Inner Diameter (in)

Kinematic Viscosity (cSt)

Fluid Density (lb/gal)

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Flow Velocity

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ft/s

Hydraulic Diameter

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Kinematic Viscosity

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cSt

Flow Type

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Reynolds Number Scale

0Laminar <2300Transitional 2300-4000Turbulent >4000

Re = ρvD / μ = vD / ν

Re < 2300: Laminar — smooth, ordered flow layers. Low friction, predictable pressure drop.

2300 ≤ Re ≤ 4000: Transitional — unstable, fluctuating between laminar and turbulent.

Re > 4000: Turbulent — chaotic mixing, higher friction factor. Most industrial pipe flow.

1 cSt = 1 mm²/s = 10&sup6; m²/s