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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.

Pro Tip: Auger capacity drops fast above 30° — a 10" auger at 45° delivers only 60% of its flat-ground rating. If your bin is tall, go up one diameter.

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 →
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Auger & Conveyor Sizing Calculator
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How It Works

  1. Select Equipment Type

    Choose portable auger, tube auger, belt conveyor, or chain/drag conveyor. Each has different base capacity ratings.

  2. Set Angle and Commodity

    Enter the auger angle (0-90°) and select your commodity. The calculator applies angle derating and commodity density factors automatically.

  3. 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

Frequently Asked Questions

Match your auger capacity to your combine unload rate. A typical large combine unloads at 300-500 BPH. A 10-inch auger at 30° delivers about 2,500-3,000 BPH — enough for one combine. Add 50% headroom for unloading two trucks simultaneously.
Capacity drops as angle increases because grain slides back. At 15°, you keep about 90% of rated capacity. At 45°, you're down to 60%. At 60°, only 40%. The derating curve is nonlinear — the first 15° costs little, but steep angles cost a lot.
Lighter, smaller, or more irregularly shaped grains flow differently through auger flights. Corn (1.0 factor) is the baseline. Soybeans (0.85) flow well but are denser. Oats (0.55) are light and bulky. Sunflowers (0.40) are the hardest to move efficiently.
Disclaimer: Capacity ratings are typical values and vary by manufacturer, auger condition, and grain condition. Consult equipment specifications for exact performance data.

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