Pipe Flow Velocity Calculator

About this calculator

This calculator finds flow velocity using v = Q/A, where Q is the volumetric flow rate and A is the pipe's cross-sectional area (πr² for a circular pipe) — a direct application of the continuity principle, which states that for an incompressible fluid, velocity must increase in a narrower pipe to keep the same volume moving through per unit time.

Plumbers and HVAC technicians sizing pipes to avoid excessive noise or erosion from high velocity, civil and mechanical engineers designing water distribution or irrigation systems, and engineering students working through fluid mechanics problems use this. Enter the flow rate and pipe diameter to get the flow velocity.