Acres Per Hour Calculator

How to use this acres per hour calculator

What this calculator does

This calculator estimates how much land a machine can cover in one hour and how long it will take to finish a specified plot. It is suitable for mowing, planting, seeding, spraying, tillage, fertilizing, and similar operations where a tool moves across the ground with a known working width. It calculates both theoretical capacity and effective capacity after overlap. It does not predict delays from turning, refilling, unloading, breakdowns, field shape, slope, wet areas, operator fatigue, or other interruptions, so the result is a planning estimate rather than a guaranteed completion time.

When to use it

Use it to compare two mower deck widths before buying equipment, estimate whether a field operation can fit into a weather window, plan labor or fuel time for a known acreage, or check how reducing pass overlap changes productivity. Iowa State University Extension explains that machine field capacity is commonly expressed in acres per hour and depends on width, speed, and field efficiency in its farm machinery selection guidance.

How to calculate

1. Enter Tool's width in feet. Use the effective cutting, planting, spraying, or working width rather than transport width.
2. Enter Speed in miles per hour. Use an average field speed that can be sustained while doing the work.
3. Enter Plot area in acres. The NIST unit tables identify one acre as 43,560 square feet; see the NIST acre conversion reference.
4. Enter Overlapping area as a percent. Ten percent means each new pass effectively adds 90% of the nominal tool width.
5. Read Area per hour and Time to complete, then review the supporting capacity cards and breakdown table. Select Download Excel to export the current inputs and results, or Reset to restore 10 ft, 5 mph, 20 acres, and 10% overlap.

Input guide

Tool's width is a required positive decimal in feet. Values such as 4.5, 10, or 30 are accepted; commas, scientific notation, and unit text are rejected. A wider tool raises capacity proportionally. Do not enter inches without first converting them to feet. Speed is a required positive decimal in mph. For example, 5 mph is reasonable for many field operations, but the correct value depends on equipment and conditions. Higher speed raises capacity proportionally, although using an unrealistic travel speed makes the estimate misleading.

Plot area is a required positive decimal in acres, such as 20 or 125. It changes completion time but not acres per hour. Do not confuse acres with square feet or hectares. Overlapping area is a required percentage from 0 through 99.99. A value of 10 means 10% of nominal width is repeated, leaving 90% field efficiency in this simplified model. More overlap reduces effective width and capacity, while 0% produces theoretical capacity. Avoid entering 100%, because that would leave no forward coverage and make completion time undefined.

Output guide

Area per hour is effective capacity in acres/hour and is the main estimate. Time to complete is the plot area divided by effective capacity and is shown in hours and minutes. Theoretical capacity assumes no overlap. Effective working width is nominal width multiplied by one minus the overlap fraction. Hectares per hour and Square feet per hour are exact unit conversions of effective capacity at the displayed precision. Overlap loss is the difference between theoretical and effective capacity. The summary pills repeat effective capacity, completion time, and field efficiency so the most important assumptions remain visible.

Worked example

With a 10 ft tool traveling at 5 mph, the theoretical capacity is 10 × 5 ÷ 8.25 = 6.06 acres/hour. A 10% overlap gives 90% effective width, so effective capacity is 6.06 × 0.90 = 5.45 acres/hour. Covering 20 acres then takes 20 ÷ 5.45 = 3.67 hours, displayed as approximately 3 h 40 min. The same effective rate equals about 2.21 hectares/hour and 237,600 square feet/hour. These values match the calculator's default state and its Excel workbook.