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Reynolds Number Calculator

Dimensionless flow regime indicator.

Compute the Reynolds number to predict whether a fluid flow is laminar, transitional, or turbulent.

Daniel Oh By Daniel Oh
Reviewed by Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

kg/m³
m/s
m
Pa·s

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

Re = ρ · v · L / μ. Pipe flow: laminar Re < 2300, turbulent Re > 4000.

In depth

Compute the Reynolds number to predict whether a fluid flow is laminar, transitional, or turbulent.