Help with nozzle inches using water meter

Hello all, I know there has been talk around here about one way to get a nozzle inch measurement, is to use your water meter and zone size.

I know roughly how long it takes to get about a half inch of water down, so I’ve used that to gauge how many inches are in an hour.

I’d like to just try the water meter way to see how close both figures are. I can use the water meter to see how many gallons are used in a certain amount of time for one zone.

What is the formula that I can plug my numbers into?


A = Area in Sq. ft.
C = Cu. In. req’d for 1 in. watering: A x 144
G = Gal. for 1 in. watering: C / 231
F = flow rate in gal. / hr. (from water meter – by zone if possible by running each zone for time period and observing gallons used)
I = in. hr.: F / G: (flow rate / gal. hr.)

Regarding measuring the area for squat foot, do you just measure what that one zone covers? What about a zone that over laps another?

Personally, I measured between the zones. Theoretically, all heads spray to the next head. So, I measure between the heads of the zones.

I was fortunate to have the original irrigation system plan that included the zone areas. I did re-measure the two zones that include nozzles that overlap the other zone, and split the overlap areas in calculating the zone areas.


( Water Used [gallons] ÷ Area [square feet] ÷ Mins duration [of the test] ) * 60 [mins - to get hourly rate]

Apart from using the Rachio Yard Map to measure a zone, you can use the following tool

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