Orifice flow calculator (liquids)

Flow through an orifice or restrictor from diameter and pressure drop.

Calculating…

How it's calculated

Q = Cd × A × √(2Δp ÷ ρ)

Flow rises with the square root of pressure: doubling Δp gives only 41% more flow. Useful for sizing restrictors and damping orifices, estimating internal leakage past a worn valve, or checking a spray nozzle.