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Calculating Sprinkler Heads Per Zone for a Well System with 20-25 GPM

Rain Bird 1800 Series Heads on a 20–25 GPM Well

The number of heads per zone depends entirely on the nozzle GPM, not just the head model. Each nozzle has a performance chart showing GPM at various pressures.

Example Calculation

Full‑circle (360°) nozzle at 40 PSI = 4 GPM each.
5 heads × 4 GPM = 20 GPM (uses full well capacity).
Half‑circle (180°) nozzle at 40 PSI = 1.5 GPM each.
12 heads × 1.5 GPM = 18 GPM (leaves margin).

Obtain nozzle charts from Rain Bird or your supplier, sum the GPM for your desired layout, and keep total zone GPM ≤ available well GPM.

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Calculating Sprinkler Heads Per Zone for a Well System with 20-25 GPM

Rain Bird 1800 Series Heads on a 20–25 GPM Well

Example Calculation

Rain Bird 1800 Series Heads on a 20–25 GPM Well