Inventory & Operations

Acres Per Hour Calculator

Estimate acres per hour from working width, speed and field efficiency. Add a target area and suitable workdays to see the deadline gap and minimum working width.

Field work, one clear plan

From working swath to workable days.

Calculate coverage, then see whether the same setup can finish your target area.

Set a realistic field rate

Use the working swath, not your machine’s overall transport width.

Width of the implement at work. Do not subtract overlap here.
Use a sustainable in-field speed, not road speed.
Includes overlap, turns, refilling and other short in-field delays.

One efficiency factor covers all those losses. Applying overlap again would understate the result.

Your working rate

How much can this setup cover?

Start with three field inputs.

Your effective acres or hectares per hour will appear here as you enter them.

Check a work window

Add a target and the field days you expect to have. This is optional if you only need the hourly rate.

Count pass-acres: covering the same area twice counts twice.
In-field working hours, excluding road travel and major repairs.
Your estimate of workable days, not calendar days or a weather forecast.

Results update as you edit. No account or upload.

Deadline check

Can this setup finish?

See the gap before the deadline.

Add the area, hours per suitable day and days available to see a completion estimate and minimum working swath.

No sign-up Private calculationsHow it’s calculated

The method

Estimate the rate, then test your work window

Theoretical field capacity is full working width in feet times ground speed in miles per hour, divided by 8.25. Effective field capacity multiplies that rate by field efficiency. In this calculator, field efficiency already includes overlap or partial passes, end-row turns, short refills and other in-field delays. Do not also reduce the entered width for overlap. For a work window, divide the area to cover by the effective rate to estimate field hours. Divide those hours by usable in-field hours per suitable day to estimate field days. To find the minimum width for a target number of suitable days, divide required acres per hour by speed and efficiency, then apply the 8.25 conversion factor. Metric calculations use meters, kilometers per hour, hectares and a factor of 10.

Theoretical field capacityFull working width (ft) × working speed (mph) ÷ 8.25 = theoretical acres/hour
Effective field capacityTheoretical acres/hour × field efficiency (%) ÷ 100 = estimated acres/hour
Work time and daily coverageField hours = pass-acres ÷ effective acres/hour; acres/suitable day = effective acres/hour × usable in-field hours/day
Minimum mathematical working width8.25 × [pass-acres ÷ (suitable field days × in-field hours/day)] ÷ [working speed (mph) × field efficiency as a decimal]
Metric field capacityFull working width (m) × working speed (km/h) × field efficiency as a decimal ÷ 10 = hectares/hour

Example 1

How many acres per hour can a disk cover?

Iowa State Extension’s worked example uses a 24-foot tandem disk at 6 mph and 80% field efficiency. The theoretical capacity is 17.45 acres/hour and estimated effective capacity is 13.96 acres/hour, rounded to 14 in the source. The 80% factor is the operator’s input in this example, not a universal default for all implements.

Working swath
24 ft
Working speed
6 mph
Field efficiency
80%
Estimated rate
13.96 acres/hour

Example 2

Can a 15-foot setup finish 900 acres in ten field days?

At 5 mph and 82% field efficiency, a 15-foot working swath covers 7.45 acres/hour and about 894.55 acres in ten 12-hour suitable field days. That is about 5.45 acres short. The minimum mathematical swath is 15.09 feet, shown as 15.1 feet by Iowa State. A 15-foot swath is slightly below that threshold; choose and verify an actual machine instead of treating the rounded number as an equipment recommendation.

Target
900 pass-acres
Available time
10 suitable days × 12 in-field hours
Current swath
15 ft at 5 mph / 82%
Minimum calculated swath
15.09 ft

Before you calculate

Assumptions & limits

  • Working swath is the implement width while operating, not the machine’s overall transport width. Enter the full working swath; field efficiency already includes overlap and partial-width passes.
  • Use a sustainable working speed and a field-efficiency estimate relevant to the actual operation and fields. Width, speed and efficiency are independent assumptions; a wider machine may run slower or lose efficiency.
  • Usable hours per field day and suitable field days are provided by the user. The calculator does not forecast weather or convert calendar days into workable days.
  • Area means the acres or hectares covered by this one operation. If the same ground is worked twice, count it twice as pass-acres. The model assumes one machine and a consistent rate.
  • Field efficiency includes in-field turns, overlap, short refills, unloading and minor delays. It does not include road travel, daily service or major repairs; equipment horsepower, safety constraints and purchasing suitability are not evaluated.
  • Inputs and results stay in this browser tab unless you deliberately copy the text estimate. No field details are included in the URL, calculation requests or analytics events.

Keep in mind

Common mix-ups

Does field efficiency include overlap?

Yes, under the Iowa State A3-24 convention used here. Enter full working swath and one total efficiency percentage. Subtracting overlap from width as well as using an efficiency estimate that already includes overlap would understate the rate.

Are suitable field days the same as calendar days?

No. Enter the number of days you expect to be able to perform this operation. Weather, ground conditions, regulations and labor can reduce suitable days; this tool does not predict them.

Why is my actual rate lower than the calculation?

Your actual speed or efficiency may differ because of field shape, crop load, refilling, turns or operator practice. Record completed acres and actual in-field hours over several jobs to calibrate an efficiency estimate.

Is the minimum working width an equipment recommendation?

No. It is the mathematical width required at the same assumed speed and efficiency. Actual standard implement widths, tractor power, transport and field conditions can change the decision.

Sources & calculation notes

Iowa State University Extension — Estimating the Field Capacity of Farm Machines (A3-24, revised February 2026)

Primary equation and definition of full operating width, field efficiency and included/excluded delays.

Iowa State University Extension — Farm Machinery Selection (A3-28)

Worked 24-foot disk and 900-acre reverse-width examples; field-day scheduling guidance.

Penn State Extension — Managing Machinery and Equipment

Independent extension explanation of width, speed, efficiency and field-shape effects.

NIST Handbook 44 — Appendix C, General Tables of Units of Measurement

Exact acre, foot and metric conversion factors used by the unit toggle.

Method and input rules checked: . Engineering validation; no professional specialist review is claimed.