Flow Rate Calculator
From Velocity & Area
Convert Flow Units
Formula
Q = v × A = v × π(d/2)²
Frequently Asked Questions
How do I calculate flow rate?
Flow rate Q = velocity × cross-sectional area. For a circular pipe: Q = v × π(d/2)². Units: m³/s, L/min, or GPM. Average household faucet: 2-3 GPM. Garden hose: 5-10 GPM.