Auger & Conveyor Sizing Calculator - BPH by Diameter, Angle & Commodity
Find the right auger diameter for your target bushels per hour with HP requirements
Select an auger diameter and see rated capacity with derating for angle and commodity type. Includes HP requirements, time-to-fill-a-bin calculations, and a full diameter comparison table so you can pick the most cost-effective size for your operation.
Know how many bushels your bin holds?
Grain Bin Capacity Calculator →Need to budget for the PTO power to run this auger?
PTO Power Budget Calculator →How It Works
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Select Equipment Type
Choose portable auger, tube auger, belt conveyor, or chain/drag conveyor. Each has different base capacity ratings.
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Set Angle and Commodity
Enter the auger angle (0-90°) and select your commodity. The calculator applies angle derating and commodity density factors automatically.
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Review Results
See derated BPH, required HP, and optionally enter bin capacity for time-to-fill estimates. Compare all diameters in the summary table.
Built For
- Farmers shopping for a new auger
- Elevator operators sizing intake conveyors
- Equipment dealers recommending the right auger for customer setups
Assumptions
- Base capacity ratings assume shelled corn at 56 lb/bu as the reference commodity (factor 1.0)
- Angle derating follows standard industry curves where capacity decreases nonlinearly above 0 degrees
- Auger flights are in good condition with no wear on flighting edges or tube walls
- Commodity density factors are applied as linear multipliers to the base BPH rating
- HP requirements assume standard PTO or electric motor drive with no excessive friction or binding
- Time-to-fill calculations assume continuous operation at the derated capacity with no downtime for truck unloading
Limitations
- Actual auger capacity varies 10-20% between manufacturers for the same nominal diameter and speed
- Worn auger flights can reduce capacity by 20-40% — this calculator assumes new or good-condition equipment
- Does not account for intake hopper design, grain moisture content above 20%, or foreign material that reduces flow
- Belt conveyor and chain drag capacities are approximate and depend heavily on belt speed and trough angle
- HP requirements do not include starting torque or the additional load from long horizontal runs before the incline
- Not applicable to pneumatic conveyors, bucket elevators, or screw conveyors with non-standard flight pitch
References
- ASABE D241.4 — Density, Specific Gravity, and Mass-Moisture Relationships of Grain for Storage
- ASABE EP389.3 — Loads Exerted by Free-Flowing Grain on Shallow Storage Structures (bulk density data)
- Batco, Westfield, Brandt — Portable Auger Capacity Charts by Diameter and Angle
- Midwest Plan Service MWPS-13 — Grain Drying, Handling and Storage Handbook (conveyor selection guidelines)
- USDA-ARS — Grain Properties and Flow Characteristics for Handling Equipment Design
- Iowa State University Extension AED-20 — Selecting Grain Handling Equipment
Frequently Asked Questions
Learn More
What Size Grain Bin Do I Need?
How to calculate grain bin capacity using real geometry, account for peaked vs level fill, factor in moisture shrink, and match your auger to the bin.
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