Harvest cost per acre for a 30 ft combine header at 4.5 mph and 75 percent efficiency is $12.22 per acre at the $150 example rate. The combine covers 12.27 acres per hour at that preset, so a 160 acre field takes 13.04 hours and costs $1,955.56 as an example figure at the page example rate.
What Harvest Cost Per Acre Means
Harvest cost per acre is the machine and operator cost of one pass of the combine across one acre. It is not the total cost of growing the crop, and it is not the price of the grain. A whole crop budget adds seed, fertiliser, chemical, rent and other costs. A hire rate is what a contractor charges. This guide stays with the machine cost of the harvest pass itself, worked from the Cost Per Acre Calculator. When the combine covers more acres in an hour, the cost on each acre falls. Readers also call this combining cost per acre. The $150 rate used here is an example rate only, not a market rate.
How Harvest Cost Per Acre Is Worked Out
Two formulas do all the work. First, acres per hour equals header width in feet times speed in miles per hour times efficiency divided by 8.25. Second, harvest cost per acre equals hourly cost divided by acres per hour. Job cost equals hours times hourly cost plus travel. The figure 8.25 equals 43560 divided by 5280. Work the preset through with unrounded figures and round only at the end. First, 30 times 4.5 times 0.75 equals 101.25, and 101.25 divided by 8.25 equals 12.272727, shown as 12.27 acres per hour. Second, 150 divided by 12.272727 equals 12.222222, shown as $12.22 per acre as an example figure at the page example rate. Third, 160 divided by 12.272727 equals 13.037037 hours, shown as 13.04 hours. Fourth, 13.037037 times 150 equals $1,955.56 as an example figure at the page example rate, with $0 travel entered.
The Combine Preset Step by Step
The calculator loads a preset when you pick a machine type. The combine preset is a 30 ft header, 4.5 mph and 75 percent efficiency. Those three values are the calculator preset values, used here exactly as stated. Treat them as the starting point, then change any value that does not match your machine. Start by picking Combine, so the calculator fills in the preset. Check the header width first, then the speed. The preset speed is 4.5 mph, a cutting speed, not a road speed.
Next, check the efficiency. The preset is 75 percent, which the calculator describes as Average, for typical conditions. Efficiency is the share of time spent cutting new ground at full width, after turns, overlap, unloading and stops. Small fields use 55 to 65 percent. Average fields use 70 to 75 percent. Large rectangular fields use 80 to 85 percent. Ideal fields with GPS guidance use 85 to 90 percent. Then enter the field size. The calculator default is 160 acres. Then enter the machine plus operator cost. The calculator default is $150 per hour, an example rate only. Finally, enter any travel and setup cost, or leave it at $0.
What Goes Into Your Hourly Cost
Your hourly cost is the most important entry, because every dollar result follows from it. Build it with care, and include every component the calculator page lists. Fuel and lubricants come first. Repairs and maintenance for the combine and the header come next. Ownership costs come next. Depreciation, interest, insurance and housing all belong in the hourly cost. Labour is the operator wage and benefits. Overheads are the last component, a share of trucks, tools and admin. No dollar figure for any component is given on the calculator page, so this guide gives none either. A common mistake is to enter fuel only, and to leave out ownership and repairs.
How Header Width Changes Harvest Cost Per Acre
Header width has a direct effect in the formula, because doubling the width doubles the acres per hour. Width, speed and efficiency carry equal weight in the formula, because each one multiplies acres per hour, so doubling any one of them doubles acres per hour. A wider header spreads the same hourly cost across more acres, so the cost on each acre falls. The table below holds speed at 4.5 mph and efficiency at 75 percent.
| Header | Acres per hour | Cost per acre |
|---|---|---|
| 20 ft | 8.18 | $18.33 |
| 25 ft | 10.23 | $14.67 |
| 30 ft | 12.27 | $12.22 |
| 35 ft | 14.32 | $10.48 |
| 40 ft | 16.36 | $9.17 |
A 40 ft header at $9.17 per acre as an example figure at the page example rate costs less than a 20 ft header at $18.33 per acre as an example figure at the page example rate, but only when the wider header can run at the same speed and efficiency. Small fields can pull efficiency down and take back the width gain. Use the guide on combine harvester productivity for the rate side.
How Speed Changes Harvest Cost Per Acre
Speed matters in the same arithmetic as width. A faster speed lowers cost per acre on paper, yet a speed that overloads the combine will lower efficiency instead. Pick a speed you can hold. The table below holds header width at 30 ft and efficiency at 75 percent.
| Speed | Acres per hour | Cost per acre |
|---|---|---|
| 3.5 mph | 9.55 | $15.71 |
| 4.0 mph | 10.91 | $13.75 |
| 4.5 mph | 12.27 | $12.22 |
| 5.0 mph | 13.64 | $11.00 |
| 5.5 mph | 15.00 | $10.00 |
The step from 4.5 mph to 5.5 mph takes the example cost from $12.22 per acre to $10.00 per acre at the page example rate. For speed by crop, see the guide on harvesting speed by crop and condition.
How Efficiency Changes Harvest Cost Per Acre
Efficiency is the number most harvest plans get wrong. Turns, unloading, adjustments, stops and overlap all take time that does not cut new ground. That time still costs money, so a low efficiency raises harvest cost per acre. The table below holds header width at 30 ft and speed at 4.5 mph.
| Efficiency | Acres per hour | Cost per acre |
|---|---|---|
| 55 percent | 9.00 | $16.67 |
| 65 percent | 10.64 | $14.10 |
| 75 percent | 12.27 | $12.22 |
| 85 percent | 13.91 | $10.78 |
| 90 percent | 14.73 | $10.19 |
The gap between 55 percent and 90 percent is large, from $16.67 per acre to $10.19 per acre as example figures at the page example rate. A large field can run at 80 to 85 percent, while a small field can fall to 65 percent or lower. Measure your own efficiency when you can.
Harvest Cost Per Acre on Small and Large Fields
Field size does not change the cost per acre when travel is $0. Field size does change the hours, the job cost and, in practice, the efficiency you can achieve. Small fields mean more turning and lower efficiency. That is why cost per acre is higher on small fields. The table below uses the combine preset at the $150 example rate, with $0 travel.
| Field size | Hours | Job cost |
|---|---|---|
| 40 acres | 3.26 | $488.89 |
| 80 acres | 6.52 | $977.78 |
| 160 acres | 13.04 | $1,955.56 |
| 320 acres | 26.07 | $3,911.11 |
Cost per acre stays at $12.22 per acre as an example figure at the page example rate in every row. Hours and job cost scale with acres. If you add travel, the job cost rises, while the cost per acre figure stays the same. For the time side, see the guide on how long to harvest 160 acres with a combine.
Own Cost Against a Hire Rate
Once you know your own harvest cost per acre, compare it with local custom rates. If a contractor rate is below your own cost per acre, hiring may make sense, as long as timeliness does not suffer. Use the custom farming rates page for the hire comparison. One rate may cover the combine only, while another covers the combine plus a grain cart and haulage. Compare like with like.
A verified custom combining survey figure is Unavailable in this guide. No survey figure is quoted here, because no authoritative survey source was opened and verified for this blog. Do not take the $12.22 per acre example figure at the page example rate as a hire rate. The first is a machine cost worked from a stated example rate and a stated preset. The second is a contractor price that may include profit, cart work and haulage. Timeliness is a decision factor, not a cost input.
How to Check Your Result and Fix a Wrong Entry
Check the result against the preset before you use it. For the combine preset at the $150 example rate, the cost per acre should sit at $12.22 per acre as an example figure at the page example rate, the rate should sit at 12.27 acres per hour, and the job cost for 160 acres should sit at $1,955.56 as an example figure at the page example rate. If your result sits far from those figures, check the header width, the speed, the efficiency and the hourly rate in that order. Check the hours with a second sum. A 160 acre field at 12.27 acres per hour takes 13.04 hours. If your hours look very different, one input is wrong. If the cost per acre looks too low, the hourly cost is often the cause.
Frequently Asked Questions
Q: What is harvest cost per acre for a combine?
A: It is the machine and operator cost of one combine pass across one acre. For the 30 ft header preset at 4.5 mph and 75 percent efficiency, it is $12.22 per acre at the $150 example rate.
Q: How do you calculate harvest cost per acre?
A: First work out acres per hour, which equals header width times speed times efficiency divided by 8.25. Then divide hourly cost by acres per hour.
Q: What is the combine preset on the cost per acre calculator?
A: The combine preset is a 30 ft header, 4.5 mph and 75 percent efficiency. At that preset the combine covers 12.27 acres per hour, and a 160 acre field takes 13.04 hours.
Q: Why does harvest cost per acre change with efficiency?
A: Because efficiency changes acres per hour. At 55 percent the preset combine costs $16.67 per acre as an example figure at the page example rate. At 90 percent it costs $10.19 per acre.
Q: Does field size change harvest cost per acre?
A: No, when travel is $0, field size does not change cost per acre. Field size does change hours and total job cost, and small fields often need a lower efficiency.
Q: Should I hire a contractor instead of running my own combine?
A: Compare your own harvest cost per acre with local custom rates. If a contractor rate is below your own cost, hiring may make sense, as long as timeliness does not suffer. A verified custom combining survey figure is Unavailable in this guide.
Plan Your Harvest Cost From the Calculator
Harvest cost per acre for a combine comes down to three entries and two formulas: header width, speed and efficiency give the rate, and the rate and your hourly cost give the cost per acre. For the 30 ft header preset at 4.5 mph and 75 percent efficiency, that chain gives 12.27 acres per hour and $12.22 per acre at the $150 example rate, with 13.04 hours and $1,955.56 for 160 acres as example figures at the page example rate. Use the cost calculator with your own figures, and read the cost per acre, the hours and the job cost together.
