Agriculture
Grain Bin Input Rate Calculator
Size grain-bin volume, fill height, safe usable capacity, aeration demand, and fan margin from grain mass, bulk density, geometry, and airflow rate.
Bin loading and aeration
Check fill height, safe capacity, and fan airflow before assigning grain to a round bin
Mass is converted through measured bulk density, then compared with usable cylindrical volume and the selected safety fill limit.Bin section
Fill surface, safe headspace, and airflow path
The cross-section scales the grain column to calculated fill height; arrows compare installed fan flow with the mass-based airflow requirement.Detailed calculation process
Convert grain mass to geometry before checking aeration
General symbolic formulas
Vg = 1000M / ρAbin = πD² / 4hfill = Vg / AbinMsafe = ρ Abin H s / 1000qreq = aM / 1000Δq = qfan − qreqThe fill calculation treats the grain surface as level and uses the cylindrical wall volume. Roof-cone storage is deliberately excluded unless included in usable wall height.
Symbols and units
Worked substitution with current inputs
Capacity and airflow check
| Check | Required / used | Available / limit | Margin | Status |
|---|
Use steps
- Use an actual test weight or bulk-density result.
- Measure inside diameter and usable vertical height.
- Enter fan delivery at operating static pressure.
Examples
Low-density grain: the same tonnes occupy more bin volume.
Deep fill: fan nameplate flow may fall as static pressure rises.
Limitations
The model excludes roof cone, hopper geometry, grain angle of repose, compaction, wall loads, moisture shrink, duct losses, static-pressure curves, and structural certification.
Grain-bin FAQ
Why exclude roof space?
Usable roof storage depends on geometry and loading limits; the conservative cylinder is easier to verify.
Is fan margin enough for drying?
No. Drying airflow, heat, weather, moisture migration, and static pressure require a dedicated design.
Can bushels be entered?
Convert bushels to mass using the actual commodity test weight before using this mass-volume model.