Catch cup results units question


Hello, I’m not sure if this has been asked before, but I just bought the Orbit Catch Cups to do the zone volume measurements. In the 1st zone I tested I surprisingly averaged 125 mL in 10 minutes out of 12 cups. The converts to 45.77 cubic inches/hr. Is this the number that I enter into the “Nozzle Inch Per Hour” box? That doesn’t make sense, it seems way too large. Are my units getting mixed up? Just seems the units for this box are a bit unclear.

Any suggestions or thoughts would be greatly appreciated. Thanks!


Try this website. You will need one catch cup area but perhaps Orbit has standardized them so the default might be OK (you’ll want to check!! Area is important in order to convert from 3D to 2D). You want inches/hr for the precipitation rate setting:


The Orbit catch cups have a 16.25 square inch opening. That means 1 inch of water will be 16.25 cubic inches. That’s 266 mL. So:

125 mL / 266 mL = .47 inches

Since you collected that in 10 minutes, you should multiply by 6 to get an hourly rate:

.47 * 6 = 2.82 inches per hour

That zone is putting down a lot of water!


After checking out that website referenced above and doing g the math I got that same number.

I too was surprised how quickly the cups were filling up.

Its interesting though, since that zone seems to be struggling the most.


I put together a spreadsheet that calculates all of this now if anyone is interested. Not sure I can upload here, but just curious.


Seems like something that should be added to the App! But I’d appreciate the spreadsheet of you can post it, or make it a google sheet to share?