How to Use Grain Bin Calculator
The Grain Bin Calculator estimates the storage capacity of cylindrical grain bins in volume (cubic meters, cubic feet, bushels) and weight (kg, metric tons, short tons). Follow these steps to get a result:
- Select dimension unit – Choose feet (ft) for US measurements or meters (m) for metric.
- Enter bin diameter – Input the inside diameter of the bin.
- Enter cylinder wall height – Input the straight-wall height from the floor to the eave.
- Add cone (optional) – Check the cone option and enter the cone height if the bin has a peaked roof or hopper bottom.
- Select grain type – Choose from corn, wheat, soybeans, barley, oats, sorghum, or rice. Select Custom to enter your own bulk density.
- Review the result – The Grain Bin Calculator displays volume in three units and estimated weight in four units.
For multi-bin farms, run the Grain Bin Calculator separately for each bin and add the totals to determine total farm storage.
Formula & Theory - Grain Bin Calculator
The Grain Bin Calculator uses this core formula or rule set, combining two geometric formulas:
Cylinder Volume V = π × r² × h
Cone Volume V = (1/3) × π × r² × h_cone
Total Volume V_total = V_cylinder + V_cone
Grain Weight W = V_total × bulk_density| Symbol | Meaning |
|---|---|
| r | Radius = Diameter ÷ 2 |
| h | Cylinder wall height |
| h_cone | Height of cone section |
| bulk_density | Grain bulk density (kg/m³) |
Standard bulk densities used in this Grain Bin Calculator:
| Grain | Density (kg/m³) | Approx. lbs/bu |
|---|---|---|
| Corn | 721 | 56 |
| Wheat | 769 | 60 |
| Soybeans | 721 | 60 |
| Barley | 625 | 48 |
| Oats | 432 | 32 |
| Sorghum | 721 | 56 |
| Rice | 577 | 45 |
Assumptions and Limits
- The calculator assumes the bin is a perfect cylinder with an optional conical cap.
- Bulk densities are approximate averages at standard moisture content.
- Allow 5–10% safety margin for aeration ducts, sensors, or equipment inside the bin.
Use Cases for Grain Bin Calculator
The Grain Bin Calculator serves farmers, grain elevator operators, agricultural engineers, and storage planners:
- Farm storage planning – Determine whether existing bins can hold a projected harvest before hauling begins.
- New bin sizing – Compare capacity across different bin diameters and heights before purchasing.
- Grain merchandising – Quickly convert bushel estimates to metric tons for international contracts.
- Feed lot management – Estimate on-site feed grain supply to plan purchase and delivery schedules.
- Construction estimation – Verify bin specifications against manufacturer capacity charts before ordering.
The Grain Bin Calculator can also help insurance appraisers and accountants estimate inventory value when physical measurement is not possible.