Pressure · flow · hydraulics

Калкулатор PSI към GPM

Оценете водния дебит с правилния системен модел.

30 practical toolsVisible formulasUS customary units
Select system

What are you calculating?

Enter conditions

Pipe run details

Estimate flow through a straight water pipe using the Hazen-Williams method.

01 System-first models02 Unit-aware inputs03 Assumptions shown04 Practical limits

Tools organized by the system you are working on

Move from a field measurement to the correct model, then inspect the formula, assumptions, and practical limits.

Method first

How PSI to GPM works

01

Identify the system

Choose pipe, nozzle, sprinkler, valve, hose, hydrant, or pump.

02

Enter physical inputs

Use actual dimensions, differential pressure, and applicable coefficients.

03

Inspect the result

Review the formula, unit convention, assumptions, and limitations.

Model selection

Choose the right pressure-to-flow method

SystemInformation neededMethod
Long pipePressure, diameter, length, materialHazen-Williams
Open nozzlePressure and opening diameterOrifice discharge
SprinklerPressure and manufacturer K-factorK-factor flow
ValvePressure drop, Cv, specific gravityValve sizing
HydrantPitot pressure, outlet, coefficientHydrant discharge

Useful answers need visible limits.

Each tool names its model, units, assumptions, and intended use. Treat the result as a practical estimate, then verify safety-sensitive work with the appropriate professional or manufacturer data.

Frequently asked questions

Pressure and flow, clarified

How many GPM is 40 PSI?

There is no single GPM value for 40 PSI. Flow also depends on the pipe, hose, nozzle, valve, sprinkler, or other path the water follows.

Does higher PSI always mean higher GPM?

Within the same unchanged system, increasing pressure generally increases flow. The relationship differs by system model.

Which pressure reading should I use?

Use the pressure difference across the component being modeled. Pipe systems use available pressure loss, hydrants use pitot pressure, and valves use valve pressure drop.

Is US GPM different from Imperial GPM?

Yes. One US gallon is about 3.785 liters, while one Imperial gallon is about 4.546 liters.