Sprinkler Zone Calculator

Enter your lawn details to estimate how many irrigation zones you need and your required flow rate. Takes 60 seconds.

Lawn Size (sq ft)

Head Type

Water Pressure (PSI)

USDA Zone

How Zone Count Is Calculated

A zone is one group of sprinkler heads controlled by a single valve, all running simultaneously. The number of zones depends on (1) how many heads you need to cover your lawn area, and (2) how many of those heads your water supply can run at once based on flow rate.

Rotor heads (Rain Bird 1800 series, Hunter PGP) cover 100–200 sq ft each and use 0.4–1.0 GPM each. Most residential water supplies can run 4–8 rotor heads per zone.

Spray heads cover 50–100 sq ft each but use 0.8–3.0 GPM — higher flow rate for their area. Keep spray heads on separate zones from rotors (different precipitation rates).

Always keep each zone's total flow demand below 75% of your available GPM to avoid pressure drop affecting coverage quality.