Acres Per Hour Calculator
Whether you are mowing, spraying, seeding, or doing any fieldwork, knowing your acres-per-hour rate helps you plan your day and quote jobs accurately. Enter your implement width, ground speed, and field efficiency to calculate your effective coverage rate.
The standard formula for field capacity is:
Acres/hour = (Width in feet x Speed in mph) / 8.25
The 8.25 constant converts square feet per hour into acres per hour (since 1 acre = 43,560 sq ft and 1 mile = 5,280 ft).
Field efficiency is the big variable. It accounts for the time spent on turns at the end of rows, overlapping passes, filling tanks or hoppers, and short stops. Here are typical efficiency values:
- Mowing (rotary/finish): 75-85%
- Mowing (zero-turn): 80-90%
- Spraying: 60-75%
- Plowing/tillage: 70-85%
- Planting/drilling: 60-75%
- Baling: 70-85%
- Combining: 65-80%
Example: A 72-inch (6 ft) zero-turn mower at 7 mph with 85% efficiency:
- Theoretical: (6 x 7) / 8.25 = 5.09 ac/hr
- Effective: 5.09 x 0.85 = 4.33 ac/hr
- That is about 34.6 acres in an 8-hour day
For commercial mowing, this calculation is essential for pricing. If you know your hourly operating cost, dividing by your effective acres per hour gives your cost per acre.