What the result means
The calculator uses the ASABE field-capacity relationship: effective width in feet × ground speed in mph ÷ 8.25 = acres per hour at 100% efficiency. The 8.25 divisor converts the foot × mph product into acres per hour (one acre = 43,560 ft², one mph = 5,280 ft/hr; 43,560 ÷ 5,280 ≈ 8.25). The efficiency slider pulls the number back toward reality for turnarounds, refills, wind checks, battery swaps, and plot shape.
If a sales claim assumes perfect field efficiency, treat it as a best-case pass rate. Operators quoting work should quote from the practical number and keep margin for ferry time and mixing.
Worked examples
Row-crop benchmark. A 30-foot swath at 12 mph has a theoretical pass rate near 43.6 acres per hour. With 10% overlap and a field day running at 75% efficiency after turns, refills, checks, and battery handling, the practical number lands near 29 acres per hour.
Assumptions to check before quoting
- The swath is the effective treated width, not just rotor span. Verify with water-sensitive paper, not the spec sheet.
- Ground speed is sustainable in the crop and terrain.
- Overlap matches the coverage requirement and wind conditions.
- Field efficiency includes refills, turns, ferry time, and short stops. ASABE typical ranges run 65–85% for ground equipment; drone work commonly lands at the lower end because of short-cycle battery and tank refills.
How to use the number
Use the practical result to compare aircraft, quote custom work, or decide whether ownership beats hiring a service. Do not use it to override pesticide-label directions, calibration checks, or state applicator requirements.
