Acre per Hour Calculator (Field Capacity)

The acre per hour calculator estimates how many acres a field machine covers in one hour, based on its travel speed, working width and field efficiency. It runs free in your browser and needs no sign-up. Enter the machine’s speed and width and an efficiency percentage, and the result appears in acres per hour and hectares per hour, together with the theoretical rate at 100 % efficiency.

Add a field size and the tool also shows how long the job takes. In More options you can add working hours per day to get the working days needed, and hours available to see how much area you can cover in a planting or spraying window. Results are planning estimates. They depend on your field, your equipment and the product label, so check them against those sources before you commit to a plan.

How to use the Acre per Hour Calculator

1. Enter your machine’s speed in the Travel speed box, then choose mph or km/h. The default is 5 mph.
2. Enter the Working width of the machine and choose ft, m or in. The default is 40 ft.
3. Enter the Field efficiency (%). The default is 75, which is only a starting point. Look up the ASABE D497 value for your machine type.
4. Optional: enter a Field size (optional) and choose acre or ha to see the time to cover it. Clear the box if you only want acres per hour.
5. Optional: open More options to enter Working hours per day (optional), which gives the working days needed, and Hours available (optional), which gives the area you can cover in that time.
6. Read the results. Effective field capacity is the realistic rate. Theoretical capacity is the rate at 100 %.
7. Open How it was calculated to see each step with your own numbers.

The example buttons above the form load “40 ft planter, 5 mph”, “90 ft sprayer, 12 mph”, “12 m at 8 km/h” and “12 ft mower, 6 mph”. Reset restores the default values. Copy link saves every input in the page address, so the same calculation reopens later. Copy result copies the result lines with a link, and Print / save as PDF prints the inputs, results, steps and date.

How do you calculate acres per hour?

Multiply the travel speed in mph by the working width in feet and by the field efficiency written as a fraction, then divide by 8.25. The answer is effective field capacity in acres per hour. The 8.25 comes from 43,560 square feet per acre divided by 5,280 feet per mile, so the units cancel out.

For example, 5 mph × 40 ft × 0.75 ÷ 8.25 = 18.182 acres per hour. In metric, the formula is km/h × width in meters × efficiency ÷ 10, which gives hectares per hour. The same job at 8.0467 km/h and 12.192 m gives 7.3579 ha/h. The tool converts units before calculating, so both systems match.

Theoretical capacity uses the same formula at 100 % efficiency. In the example, that is 24.242 acres per hour. To find the time for a field, divide the field size by the effective capacity. A 160-acre field takes 160 ÷ 18.182 = 8.8 hours. At 10 working hours per day, that is 0.88 working days.

What is field efficiency?

Field efficiency is the percentage of the theoretical rate that a machine actually achieves across a whole job. The remainder is lost to turning at the ends of rows, overlap between passes, filling the tank or hopper, and unloading. A lower efficiency means fewer acres per hour, so it has a large effect on planning.

Typical values by machine type are published in ASABE D497. Look up your machine’s value rather than relying on one figure, because 75 % is only a starting point. The tool warns when the value is below 50 %, in case you meant a higher number. It also warns above 90 %, because real fields lose time to turning, overlap and filling.

How many acres can a machine cover in a day?

Multiply the effective capacity by the hours you work. At 18.18 acres per hour and 10 hours, that is about 182 acres. Enter the hours in Hours available to get this directly. Working days are rarely full, because weather, breakdowns and refills cut into the hours, so treat the number as a best case.

Sources

• Iowa State University Extension PM 696, Estimating Field Capacity of Farm Machines — field capacity = speed × width × efficiency ÷ 8.25 (ASABE EP496) and typical field efficiencies by implement
• NIST Handbook 44, Appendix C and NIST SP 811 — exact unit definitions (1 acre = 43,560 ft² = 4,046.8564224 m², 1 lb = 0.45359237 kg, 1 US gal = 231 in³)

Worked examples

Calculated by the tool above with these values.

Frequently asked questions

Is the calculator free, and is anything I type uploaded?

Yes, the calculator is free. It runs entirely in your browser and needs no sign-up. Nothing you type is uploaded.

Can I use the results in commercial work such as quotes and bids?

Yes. Results, steps and printouts may be used in any work, including commercial work such as quotes, invoices, spray records and nutrient plans. No attribution is needed. Still, check figures against your product label and field data before you promise a client a timeline.

What do the efficiency warnings mean?

A low warning means the value may be wrong, so check whether you meant a higher figure. A very high warning reminds you that real fields lose time to turning, overlap and filling. In that case, check the ASABE D497 value for your machine type.

Why is theoretical capacity higher than effective capacity?

Theoretical capacity assumes 100 % efficiency, with no turning, overlap or stops. Effective capacity uses your efficiency figure, so it is the rate to plan with. The gap between the two is the time lost in the field.

What does “Area you can cover in the hours available” mean?

It multiplies your effective field capacity by the hours available. For example, at 18.18 acres per hour and 8 hours available, you can cover about 145 acres. Use it to check whether a planting or spraying window is long enough.

Does the calculator tell me what rate to apply?

No. It calculates field capacity, time and working days, but not application rates. The product label, a soil test, an agronomist, the extension service or a veterinarian gives the actual recommendation.

Related tools

• Square foot to acre converter: use it to convert field areas given in square feet into acres before you enter a field size.
• Hectare to acre converter: use it when your field size or results are in hectares and you need acres.
• Acreage calculator: use it to work out the area of a field from its dimensions.
• Fertilizer calculator: use it to work out product amounts for a fertilizer application over an area.
• Lawn fertilizer calculator: use it to estimate fertilizer needs for a lawn.
• Lime calculator: use it to estimate lime amounts for an area.
• Seeding rate calculator: use it to work out seed quantities for a planting job.
• All calculators: use it to browse every tool on this site.