basic

Pipe Internal Diameter & Flow Rate Calculator

Q = A × v — flow rate from pipe cross-section and velocity.

Calculates volumetric flow rate, pipe cross-sectional area, and mean velocity for round pipe flow from diameter and velocity.

Priya Venkatesan By Priya Venkatesan
Published Last reviewed 1 min read

Inputs

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

A = π×D²/4; Q = A × v; D = √(4Q/(π×v))

In depth

Calculates volumetric flow rate, pipe cross-sectional area, and mean velocity for round pipe flow from diameter and velocity.