Calculate your sprayer application rate in gallons per acre from nozzle flow, ground speed and nozzle spacing, plus the total flow across the boom.
Application rate from nozzle flow and ground speed
The standard broadcast-spraying formula converts nozzle flow, ground speed and nozzle spacing into an application rate in gallons per acre:
GPA = (5,940 × GPM per nozzle) ÷ (MPH × nozzle spacing in inches)
5,940 is a unit-conversion constant that combines square feet per acre, inches per foot, and feet per mile. Total boom flow is the number of nozzles (boom width in inches ÷ spacing) times the flow per nozzle.
Example: 0.4 GPM nozzles on 20-inch spacing at 10 mph apply (5,940 × 0.4) ÷ (10 × 20) = 11.88 gallons per acre. A 60-foot boom carries 36 nozzles for a total flow of 14.4 gallons per minute.