Estimate US bushels in a round bin from diameter, eave (sidewall) height, and optional peak height for a conical roof pack.
Use this for planning fill volume of a cylindrical farm bin when you know diameter and grain height to the eaves, and optionally how tall the peaked cone of grain (or roof peak pack) is.
US bushel packing uses 1.2445 cubic feet per bushel. Packing factor and moisture affect real scale tickets.
Cylinder volume plus optional cone volume, then divide cubic feet by 1.2445 for US bushels.
r = diameter ÷ 2
cu_ft_cyl = π × r² × eave_height
cu_ft_cone = (1/3) × π × r² × peak_height (if peak > 0)
bushels = (cu_ft_cyl + cu_ft_cone) ÷ 1.2445
Bin 30 ft diameter, 18 ft grain to eaves, 4 ft peak:
r = 15 → cyl ≈ 12,723 cu ft; cone ≈ 942 cu ft; total ≈ 13,665 cu ft → ≈ 10,980 bushels.
Assumptions: perfect cylinder/cone geometry; level fill to entered heights; standard US bushel 1.2445 cu ft.
Limits: ignores packing, moisture shrink, hopper bottoms, and aeration floor displacement. Manufacturer charts may use test weight adjustments.
Responsibility: do not overload structural capacity — follow bin manufacturer limits.
That is the common US dry volume bushel used in many grain-bin capacity charts (2,150.42 cu in ≈ 1.2445 cu ft).
Enter the actual grain height as eave height and set peak to 0 unless you have a cone below the eaves.
This page models a flat-floor cylinder plus optional top cone. Hopper volume needs a separate frustum calculation.