What is acres per hour?
Acres per hour (ac/hr) is a coverage rate: how much land a machine can work in one hour. It is the number every operator uses to plan planting windows, spray days, harvest crews, hay schedules and contract pricing. If a planter covers 12 acres per hour, a 160-acre field is roughly 13 hours of planting, simple to say, but only if the rate is right.
Two things set the rate: how wide the machine works, and how fast it moves. The third factor most people forget is field efficiency: the share of time the machine is really working rather than turning, refilling, unloading or waiting. This calculator combines all three so you get a number you can plan around, not a brochure figure.
If you searched for a how many acres per hour calculator (or an acre per hour calculator, in the singular), this is it: choose your machine, confirm the working width and speed, and the answer appears as you type. It also tells you how long your field will take, how many acres you can finish in a day and what you would need to hit a deadline. There is nothing to install, and it works on a phone in the cab.
The acres per hour formula
Where does 8.25 come from? An acre is 43,560 square feet, and a mile is 5,280 feet. Traveling at 1 mph with a 1-foot-wide implement covers 5,280 square feet per hour. Divide 43,560 by 5,280 and you get 8.25. So at 100% efficiency, a machine working 1 ft wide at 1 mph covers 1 ÷ 8.25 = 0.1212 acres per hour.
Quick mental math: width × speed × efficiency ÷ 8.25 ≈ width × speed × efficiency × 0.12. A 30-ft planter at 5 mph and 70% efficiency: 30 × 5 = 150; × 0.7 = 105; × 0.12 ≈ 12.7 acres per hour.
Some sites divide by 1,000 or use rounded constants. Those shortcuts drift away from the true value. This tool uses the exact 43,560 ÷ 5,280 constant, so what you see is what the geometry gives you.
Overlap and efficiency
Some tools ask for an overlap percentage instead. Overlap simply shrinks the width you actually cover: effective width = width × (1 − overlap). A 10% overlap on a 30-ft implement leaves 27 ft of new ground per pass, which is the same as multiplying the result by 0.90. Here, overlap is part of field efficiency along with turning, refilling and stopping, so you only need one number.
Metric version (hectares per hour)
To convert, 1 hectare = 2.471 acres, so 1 acre = 0.4047 hectares. The calculator shows the metric equivalent under “Metric”.
Typical acres per hour by equipment
The table below shows what common machines cover with typical settings. Pick the equipment type in the calculator to start from these values, then adjust width, speed and efficiency for your own setup.
| Equipment | Width | Speed | Efficiency | Acres / hour |
|---|---|---|---|---|
| Zero-turn / riding mower (60 in deck) | 5 ft | 6 mph | 80% | 2.9 |
| Bush hog / rotary cutter (6 ft) | 6 ft | 4 mph | 75% | 2.2 |
| Tractor + tandem disk (20 ft) | 20 ft | 6 mph | 80% | 11.6 |
| Field cultivator (40 ft) | 40 ft | 6 mph | 80% | 23.3 |
| 12-row planter, 30 in rows (30 ft) | 30 ft | 5 mph | 70% | 12.7 |
| 16-row planter, 30 in rows (40 ft) | 40 ft | 5 mph | 70% | 17.0 |
| Combine, 30 ft header | 30 ft | 3.5 mph | 70% | 8.9 |
| Self-propelled sprayer (90 ft boom) | 90 ft | 12 mph | 65% | 85.1 |
How to choose your field efficiency
Field efficiency is the ratio of effective field capacity (what you actually cover per hour, including all the non-productive time) to theoretical field capacity (what the machine would cover if it worked at full width and speed without ever stopping). It is the single biggest reason real-world results fall short of the theory.
| Situation | Typical field efficiency |
|---|---|
| Large, square fields, GPS auto-steer, few stops | 85–90% |
| Average farm fields, well-organized logistics | 75–85% |
| Planting or spraying with frequent seed / tank refills | 60–75% |
| Small, irregular or hilly fields, many obstacles | 50–65% |
| Mowing open pasture with a wide cutter | 75–85% |
| Mowing lawns with trees, beds and trimming | 55–70% |
What eats into efficiency:
- Turning at headlands: more turns per acre in short or narrow fields.
- Overlap and skips: hand steering overlaps more than GPS guidance.
- Refilling and unloading: seed, chemical, fuel and grain-cart transfers.
- Field shape and obstacles: point rows, waterways, trees, power poles.
- Terrain and soil conditions: slopes and wet spots force slower speeds.
- Breakdowns, adjustments and operator changes.
The best way to get an accurate number is to record your own: cover a known field, note the hours from the tractor’s hour meter or monitor, then divide acres by hours. Once you have that, divide it by the theoretical rate to get your true efficiency.
Worked examples
Example 1: 12-row planter
A 12-row planter on 30-inch rows works 30 ft wide. At 5 mph and 70% efficiency: (30 × 5 × 0.70) ÷ 8.25 = 12.7 acres per hour. A 160-acre field takes about 12.6 hours. Next, size your seed order with the seeding rate calculator and check the stand afterwards with the plant population calculator.
Example 2: Field cultivator
A 40-ft field cultivator at 6 mph and 80% efficiency: (40 × 6 × 0.80) ÷ 8.25 = 23.3 acres per hour. Over a 10-hour day that is about 233 acres.
Example 3: Ground sprayer
A 90-ft boom at 12 mph with 65% efficiency (tank refills are frequent): (90 × 12 × 0.65) ÷ 8.25 = 85.1 acres per hour. For nozzle output and tank mixing, use the sprayer gallons per acre calculator.
Example 4: Zero-turn mower
A 60-inch deck is 5 ft wide. At 6 mph and 80%: (5 × 6 × 0.80) ÷ 8.25 = 2.9 acres per hour, so 5 acres takes about 103 minutes. See the mowing calculator for mower-specific presets.
Acres per hour calculator for spraying
Spraying uses the same formula, with the boom width as the working width. A 90-ft boom at 12 mph and 65% efficiency covers 85.1 acres per hour. The efficiency is lower than tillage because tank refills, nozzle checks and turning on and off at headlands take real time. To see it for yourself, open the acres per hour calculator with the sprayer preset and change the boom width, speed and efficiency to match your rig.
Acres per hour tells you how fast you cover ground. It does not tell you how much liquid goes on each acre. For that, use the sprayer gallons per acre calculator, which handles nozzle flow, speed, tank mixes and calibration. To compare booms of different sizes side by side, see the boom sprayer preset in the farm equipment calculator.
Field capacity: theoretical vs. effective
Agricultural engineers call the same idea field capacity. Theoretical field capacity assumes 100% efficiency; effective field capacity is the theoretical value multiplied by your field efficiency, exactly the number in the big result box. This calculator shows both, so it doubles as a field capacity calculator: the “Theoretical (100%)” tile is your ceiling, and the main result is what you should plan on.
Work time and acres per day
Enter a field size and your working hours per day to turn the rate into a schedule. The calculator returns:
- Time to finish the field = acres ÷ acres per hour.
- Acres per day = acres per hour × working hours.
- Days needed = field acres ÷ acres per day.
Be realistic about hours: daylight, dew, weather windows and operator fatigue all cap the productive workday. Planning with 8–10 hours often beats optimistic 14-hour assumptions.
You have 1,200 acres to plant and a machine that covers 12.7 ac/hr. At 10 hours a day that is 127 acres/day, about 9.4 planting days. If your realistic planting window has only 6 workable days, you need a wider planter, a second machine, or higher efficiency.
Working backwards from a deadline
Enter a field size and a deadline in machine hours to reverse the calculation. The calculator shows the coverage rate you need, then the width you would need at your current speed, or the speed you would need at your current width. If the speed comes out unrealistic, the answer is a wider machine, a second machine or better efficiency, not a faster tractor.
Common mistakes to avoid
- Using tractor width instead of implement width. The rate depends on the working width of the tool.
- Using 100% efficiency. No real machine works at 100%.
- Mixing units. Feet with mph, or meters with km/h, not a mix of both. The unit selectors here convert for you.
- Using top speed instead of working speed. Use the speed you actually hold while working, often lower than the machine’s maximum.
- Ignoring refill time. Sprayers and planters lose meaningful time to tank and hopper refills.
- Forgetting the day length. An hourly rate only becomes a schedule once you apply realistic hours.
How to increase your acres per hour
- Go wider. A wider implement raises capacity directly, if your tractor and fields can handle it.
- Cut non-productive time. Bigger tanks and hoppers, tender trucks, staged refills and grain carts all raise efficiency.
- Use guidance. Auto-steer and section control reduce overlap and skips.
- Run longer passes. Fewer headland turns per acre. Where possible, consolidate small fields into work blocks.
- Match speed to conditions. Faster is only better if quality (seed placement, spray coverage, cut) holds up.
- Keep equipment in shape. Sharp blades, tuned tires and pre-season maintenance prevent slow-downs and breakdowns.
Next: not sure of the acreage? Use the acreage calculator to measure the field first. Pricing a job? Try the bush hog cost calculator.
Which calculator do you need?
- Mowing a lawn or pasture: the mowing acres per hour calculator answers how long it takes to mow an acre, or any lot size.
- Spraying: the sprayer gallons per acre calculator for GPA, nozzle flow, tank mix and calibration.
- Cutting brush with a tractor: the bush hog acres per hour calculator, then the cost to bush hog per acre if you are deciding whether to hire.
- Tillage, planting, baling or harvest: the farm equipment acres per hour calculator with twelve implement presets.
- How much seed to buy: the seeding rate calculator, and the plant population calculator to check your stand.
- Clearing trees and brush: the land clearing cost calculator.
- Measuring a field or lot: the acreage calculator for any shape, plus unit conversions.
Use it as an acres per hour calculator app
You do not need to download anything from an app store. The site works as a lightweight acres per hour calculator app on your phone:
- iPhone or iPad (Safari): tap Share, then Add to Home Screen.
- Android (Chrome): open the menu, then choose Install app or Add to Home screen.
After the first visit, the calculators keep working without signal, which helps in the cab or at the back of a field. Nothing you type is stored on our servers. Use Copy link or Copy result to share a calculation with your crew.
Key terms
- Working width (swath width)
- The width of ground an implement actually treats in one pass. Use this, not the tractor or transport width.
- Ground speed
- How fast the machine moves across the field while working, in miles per hour (mph) or kilometers per hour (km/h).
- Field efficiency
- The share of time and width that is truly productive after turning, overlap, refilling and stopping, expressed as a percentage.
- Theoretical field capacity
- Acres per hour at 100% efficiency: width × speed ÷ 8.25.
- Effective field capacity
- Theoretical capacity multiplied by field efficiency. This is the number to plan with.
- Headland
- The strip at the end of a field where machines turn. More headland turns per acre means lower efficiency.
- Overlap
- Ground covered twice between adjacent passes. It shrinks the effective width.
- Implement
- The tool a tractor pulls or carries, such as a disk, planter, cutter or sprayer. It sets the working width.
- Acre and hectare
- Units of land area. One acre is 43,560 square feet (0.4047 hectares); one hectare is 2.471 acres. See the acreage calculator for conversions.
Frequently asked questions
How do you calculate acres per hour?
Multiply the working width in feet by the travel speed in miles per hour and the field efficiency (as a decimal), then divide by 8.25. Example: 30 ft × 5 mph × 0.70 ÷ 8.25 = 12.7 acres per hour.
What is a good field efficiency percentage?
Most field operations fall between 65% and 85%. Big square fields with auto-steer can reach 85–90%, while small or irregular fields, or operations with frequent refills such as spraying and planting, can drop to 50–65%. The best number is the one you measure on your own farm.
How many acres per hour can a tractor do?
A tractor has no fixed acres-per-hour figure: the implement it pulls sets the rate. A tractor with a 20-ft disk at 6 mph and 80% efficiency covers about 11.6 acres per hour; the same tractor with a 6-ft rotary cutter at 4 mph covers about 2.2. Choose the implement in the calculator and enter its working width.
How many acres per hour does a combine harvest?
A combine with a 30-ft header traveling 3.5 mph at 70% efficiency harvests roughly 8.9 acres per hour. Actual rates depend on crop, yield, moisture, grain-cart logistics and the machine’s throughput limit, so treat this as a planning estimate and confirm against your own harvest records.
How do I convert acres per hour to hectares per hour?
Multiply acres per hour by 0.4047. Or use the metric formula directly: width in meters × speed in km/h × efficiency ÷ 10. The calculator shows the metric equivalent beneath the main result.
How many acres per day can I cover?
Acres per day = acres per hour × productive hours per day. Enter your working hours in the calculator and it does this automatically. Use realistic hours. Dew, daylight and fatigue mean many operations average 8–10 productive hours.
Why is my real-world rate lower than the calculator result?
Usually the efficiency setting is too high or the speed is too optimistic. Log a full field with your hour meter, divide acres by hours to get your true effective rate, and use that to calibrate your efficiency figure.
Is there an acres per hour calculator for spraying?
Yes. Choose Sprayer in the equipment list, or open the acres per hour calculator spraying preset directly. Enter your boom width, travel speed and field efficiency for a coverage rate in acres per hour.
Is there a mower acres per hour calculator?
Yes, choose Mower here for a quick answer, or use the dedicated mowing acres per hour calculator, which has presets for push mowers, riding mowers and zero-turns.
Does this work as a planting or combine acres per hour calculator?
Yes. Choose Planter for an acres per hour planting calculator, or Combine for a combine acres per hour calculator. Both use the same width x speed x efficiency formula, with presets you can edit.
How do I convert mph to acres per hour?
Speed alone is not enough: multiply mph by the working width in feet and by field efficiency, then divide by 8.25. That is what this mph to acres per hour calculator does once you enter width and efficiency.
Is 'acres covered per hour' the same as acres per hour?
Yes, they describe the same measure: width (ft) x speed (mph) x field efficiency ÷ 8.25.
What is an acre per hour calculator?
An acre per hour calculator (also written acres per hour calculator) estimates how much land a machine covers each hour from its working width, speed and field efficiency. This page does that for tractors, planters, combines, sprayers, bush hogs and mowers.
Can I use this for mowing and spraying?
Yes. Choose Mower or Sprayer in the equipment list. For deeper tools, see the mowing acres per hour calculator and the sprayer gallons per acre calculator.
Sources and further reading
The formulas on this page are standard and can be checked against these references. Where a figure is a planning range rather than a measurement, the page says so.
- Calculating Mowing Times and Productivity (Encore Equipment) – the width x speed x efficiency method for mowing capacity
Concepts on this page: Acre · Hectare · Tractor · Combine harvester · Sprayer · Lawn mower · Agricultural machinery