Two operators with identical machines can finish the same field hours apart. Almost all of that difference comes down to field efficiency: the share of time the machine spends covering new ground at full width.
What field efficiency means
The theoretical rate assumes the machine never stops, never turns and never overlaps. Real work always falls short, and field efficiency captures by how much.
Typical ranges
| Efficiency | Typical situation |
|---|---|
| 55 to 65% | Small, irregular fields; many obstacles; frequent stops |
| 70 to 75% | Average farm fields and properties |
| 80 to 85% | Large, rectangular fields with good logistics |
| 85 to 90% | Ideal conditions with GPS guidance and minimal overlap |
What reduces efficiency
- Turning at headlands. The single biggest loss in small fields, because the number of turns rises as fields get shorter.
- Overlap. Overlapping 1 ft on a 10 ft implement wastes 10% of the width.
- Refills and unloading. Seed, fertilizer, chemical and grain logistics often cost more time than turning.
- Point rows and odd corners. Triangular sections force short passes.
- Obstacles. Trees, poles, wet holes and rocks slow everything down.
- Adjustments and breakdowns. Unclogging, greasing and small repairs add up over a day.
How much difference does it make?
A 15 ft disc at 5 mph covers 9.09 acres per hour in theory. At 85% efficiency that is 7.73 ac/hr; at 65% it is 5.91 ac/hr. On 100 acres that is the difference between 12.9 and 16.9 hours of work.
How to measure your own efficiency
- Record the field size and the total time from first pass to last, excluding travel to the field.
- Work out actual acres per hour: acres ÷ hours.
- Work out theoretical acres per hour: width × speed ÷ 8.25.
- Divide actual by theoretical. That is your efficiency for that field.
Repeat across a few fields and keep a simple log. Most operators are surprised to find they run between 65 and 75%, which is why using 85% in a quote often leads to long days.
Ways to improve it
- Plan passes along the longest side of the field to reduce turns.
- Keep supply vehicles close: a nurse tank at the field edge can save many minutes per refill.
- Use guidance systems or careful markers to cut overlap.
- Service equipment before the season so small failures don’t stop work.
- Scout fields and mark hazards before you start.
Try different efficiency settings in the Acres Per Hour Calculator to see how much time a small improvement saves over a season.