Flow Rate Calculator — Q = Av

The volume passing per second equals the cross-section times the speed — the basis of the continuity equation: narrow the pipe and the fluid speeds up.

How to interpret the result

A garden hose (2 cm²) flowing at 3 m/s delivers 0.6 L/s — about 36 liters per minute.

Assumptions

• Incompressible, steady flow
• Uniform velocity across the section