Flow Rate
Estimator
Enter a known flow rate at a catalog reference pressure to estimate the flow at your actual operating pressure. Based on the standard spray nozzle flow-pressure relationship: Qโ = Qโ ร โ(Pโ รท Pโ).
Enter catalog flow rate, reference pressure, and your operating pressure โ then tap Calculate.
The Flow-Pressure Formula
For hydraulic spray nozzles, flow rate scales with the square root of operating pressure โ not linearly. This formula converts any catalog flow rate to a flow estimate at a different pressure.
Qโ = known catalog flow rate ย |ย Pโ = catalog reference pressure ย |ย Qโ = estimated flow at new pressure ย |ย Pโ = your operating pressure
All pressures must be in the same unit. The result is in the same unit as Qโ. This tool converts units automatically so you can mix PSI, bar, and kPa entries.
Three Common Examples
Flow Multipliers at Common Pressures
Multiply the catalog GPM by the multiplier to estimate flow at any listed pressure. Catalog reference = 40 PSI (โ ).
| Operating Pressure | In bar | Flow Multiplier | % Change | Visual |
|---|---|---|---|---|
| 10 PSI | 0.69 bar | 0.50ร | โ50% | |
| 20 PSI | 1.38 bar | 0.71ร | โ29% | |
| 30 PSI | 2.07 bar | 0.87ร | โ13% | |
| 40 PSI โ | 2.76 bar | 1.00ร | โ | |
| 50 PSI | 3.45 bar | 1.12ร | +12% | |
| 60 PSI | 4.14 bar | 1.22ร | +22% | |
| 80 PSI | 5.52 bar | 1.41ร | +41% | |
| 100 PSI | 6.89 bar | 1.58ร | +58% | |
| 150 PSI | 10.34 bar | 1.94ร | +94% | |
| 200 PSI | 13.79 bar | 2.24ร | +124% |