How do I find a pipe's cross-sectional area?

For a circular pipe, area = π × (diameter/2)². Use the circle calculator to find this if you only know the pipe's diameter.

Does this assume uniform flow across the pipe?

Yes, this gives the average velocity assuming uniform flow. Real flow profiles (especially in laminar flow) vary across the cross-section, being fastest at the center.

Fluid Velocity Calculator

Calculate the average velocity of fluid moving through a pipe or channel, given the volumetric flow rate and the cross-sectional area. A core calculation in plumbing, HVAC, and fluid dynamics design.

Inputs

Results

Fluid Velocity: 2 m/s

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Formula

v = Q / A (Flow Rate ÷ Cross-Sectional Area)

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Rotational and Fluid Dynamics for Engineers

Pipe flow rate, RPM-to-linear-speed conversion, moment of inertia, natural frequency, and fluid velocity — five calculations for rotating and flowing systems.

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