Sprinkler Friction Loss Calculator

Tolerable Pressure Loss

Friction loss is traditionally used to size laterals. It is best not to exceed 5% friction loss in laterals.

Note; I generally stick to the feet per second method for laterals on residential properties, because it is much easier to calculate for every location in a given system.

Available PSI

Longest Run/Longest zone

The longest run is the distance from the valve to the furthest sprinkler head (following the path of the lateral piping.)

Allowable PSI Loss by Percentage

The allowable percentage loss is simply the total allowable PSI drop over distance. This is generally 5%

Allowable PSI Loss Per 100 Feet

As always, check the outcome and calculations, do not depend on this tool to be accurate. We strive hard to build a perfect tool, but it is possible that there are flaws or bugs in the programming or calculations.