Combine Capacity Calculator

Harvest rate from header, speed, and yield.

Header width (ft)

Harvest speed (mph)

Field efficiency (%)

Crop yield (bu/acre)

Grain tank capacity (bu)

Harvest hours/day

Tab to move between fields

Acres/hour

8.91

Bushels/hour1,604

Tank fill time (min)11.2

Acres/day106.9

Bushels/day19,244

Unloads/day64.1

How to Use This Calculator

Enter Header Width (ft) for your corn head or grain platform.
Set Harvest Speed (mph) — typical combines run 2.5–5 mph depending on crop and yield.
Set Field Efficiency (%) to account for turns, unloading stops, and downtime (60–75% is typical for combines).
Enter Crop Yield (bu/acre) and Grain Tank Capacity (bu) for your specific situation.
Review Acres/Hour, Bushels/Hour, Tank Fill Time (min), Acres/Day, and Unloads/Day to plan grain cart logistics.

How the result changes with Header width (ft)

Header width (ft): Cutting platform or corn head width in feet.
Harvest speed (mph): Ground speed during harvest. Typically 2.5-5 mph depending on crop and yield.
Field efficiency (%): Accounts for turns, unloading, and downtime. Combines typically 60-75%.
Crop yield (bu/acre): Expected crop yield in bushels per acre.
Grain tank capacity (bu): Combine grain tank capacity in bushels.
Harvest hours/day: Available harvesting hours per day.

Acres/hour: Effective field capacity in acres harvested per hour.
Bushels/hour: Grain throughput in bushels per hour.
Tank fill time (min): Minutes until the grain tank is full and needs unloading.
Acres/day: Total acres harvested in one day.
Bushels/day: Total bushels harvested per day.
Unloads/day: Number of grain tank unloads required per day.

Identify Input Parameters
4 parameters
Header width (ft) = 30, Harvest speed (mph) = 3.5, Field efficiency (%) = 70, Crop yield (bu/acre) = 180 = 6 input(s) provided
Calculate Acres/hour
Acres/hour = (speedMph * headerWidthFt * efficiency) / 8.25
8.91 = 8.91
Calculate Bushels/hour
Bushels/hour = efcAcresHr * yieldBuAcre
1604 = 1604
Calculate Tank fill time
Tank fill time = tankFillTimeHr * 60
11.2 = 11.2