Spray Nozzle Calculator

It falls out of reconciling the units involved: gallons per acre, miles per hour, and inches of nozzle spacing don't combine into gallons per minute without a conversion factor, and 5940 is that factor once acres, miles, and inches are all resolved to a common basis. It's a fixed unit-conversion constant, not an adjustable or empirical value.

GPM per nozzle is determined entirely by application rate, ground speed, and nozzle spacing — boom width never enters that formula. The calculator only uses a 60-foot reference boom afterward to estimate how many nozzles fit and what the combined boom output would be, so if your actual boom differs from 60 feet, treat total boom GPM, acres-per-hour, and spray time as illustrative rather than exact for your setup.

Nozzle flow scales with the square root of pressure, so if you're spraying at a pressure other than 40 PSI, your actual required GPM won't match what's printed on a nozzle catalog sheet, which is standardized to a 40 PSI reference. The calculator divides your required GPM by the pressure correction factor (square root of your PSI over 40) to give you the equivalent 40 PSI rating to shop for — using this figure instead of your raw required GPM is what makes catalog nozzle selection correct.

Acres per hour is derived from ground speed and the 60-foot reference swath using the standard 495 conversion constant (43,560 ÷ 88), then field acres divided by that rate gives total spray time in minutes. This excludes time spent on tank refills and end-of-row turns, so real-world time in the field will run longer than the estimate.