Spray Rate Calculator
Enter your field size, application rate, and tank size to calculate total spray volume and number of tank loads.
2
tank loads
600
total gallons
For 40 acres at 15 GPA with a 300-gallon tank:
- • 600 gallons total spray needed
- • 2 full tank loads (300 gal each)
- • Last tank: 300 gallons
Spray Rate Formula
Total Volume = Field Area (acres) x Application Rate (GPA)
Tank Loads = Total Volume / Tank Size
GPA = Gallons Per Acre. Common rates: herbicides 10-20 GPA, fungicides 15-25 GPA, liquid fertilizer 20-40 GPA.
GPS-Guided Spraying
FieldMate's spraying mode with GPS guidance lines ensures full coverage with zero overlap — saving chemicals and fuel.
Try FieldMate FreeFAQ
What is a good spray rate per acre?
It depends on the product. Herbicides typically use 10-20 gallons per acre (GPA), fungicides 15-25 GPA, and liquid fertilizer 20-40 GPA. Always follow the product label for recommended rates.
How do I calculate how many tank loads I need?
Divide total spray volume by your tank size. Total volume = field acres x application rate (GPA). For example, 100 acres at 15 GPA = 1,500 gallons. With a 300-gallon tank, that's 5 tank loads.
What does GPA mean in spraying?
GPA stands for Gallons Per Acre — the volume of spray mix applied per acre. It's determined by nozzle output, pressure, and ground speed. Higher GPA means more coverage but more refills.
How does GPS guidance help with spraying?
GPS guidance lines prevent overlap and skips. Without guidance, operators typically overlap 10-15% — wasting chemicals and risking crop damage from double-sprayed strips. GPS can reduce overlap to under 5%.