Estimate bin capacity, usable storage, dry weight, and moisture shrink
Bin diameter, eave (straight-wall) height, and optional roof cone height are used to compute total geometric volume in cubic feet. The roof cone is treated as a right circular cone atop the cylinder.
Selecting a grain sets the standard bulk density in lbs per bushel. Each grain also has a standard moisture reference for shrink calculations.
Entered moisture is compared against the grain's standard reference moisture. The difference drives moisture shrink: water weight is lost during drying, reducing effective dry weight.
Grain piled in a bin forms a peak cone. Usable storage is the cylinder volume minus a small headspace margin and adjusted for the peak. Typical peak adds 2-4% capacity depending on fill angle.
Total bushels = geometric volume (ft³) × fill factor ÷ 1.2446 ft³/bushel (industry standard). Usable capacity subtracts typical headspace (6 inches) and adjusts for peak angle.
Dry tons are calculated from bushels × bulk density ÷ 2000, then adjusted for moisture shrink if the grain is wetter than standard.
Shrink percent = (actual moisture − standard moisture) ÷ (100 − standard moisture) × 100. This represents the percentage of wet-weight that is lost as water during drying to the standard level.