@dthornburg84, sorry for any confusion on custom nozzles. For a 2 GPH drip emitter, a 1 square foot coverage (assuming drip line placement), the precip rate would be 3.21 in/hour.
I think it would help to step back and rethink the calculation. The precip rate (PR) is not the same as the flow rate. Let's break down the equation for everyone to better understand:
PR = (96.25(A*B))/(C)
96.25 = constant that converts gallons per minute (GPM) to inches per hour. It is derived from 60 minutes per hour divided by 7.48 gallons per cubic foot. times 12 inches per foot.
A = #heads -or- #emitters
B = flow rate (GPM) per head -or- emitter
C = zone square footage
I hope this helps. For a detailed explanation, please reference this article
Love this idea! We'll look into creating this...or better yet, a custom nozzle calculator