Grain Bin Calculator — Bushel Capacity & Weight
Enter your grain bin's diameter, eave (sidewall) height, and grain type to instantly calculate the storage capacity in bushels, the estimated total weight in pounds, short tons, and metric tonnes, and the added capacity from the peaked roof cone.
ft
ft
Grain type
Bushels stored in the straight-wall cylinder only
- 1
Cylinder volume
π ÷ 4 × 30² × 24 = 16,964.6Volume of the straight-wall cylinder in cubic feet. - 2
Bulk density ÷ test weight
44.8 ÷ 56 = 0.8 - 3
Bin capacity
16,964.6 × 0.8 = 13,572
How does this calculator work?
Bin capacity (bushels) = (π/4 × D² × H) × (bulk density / test weight). For a 30-ft-diameter, 24-ft-tall corn bin the cylinder holds roughly 16,200 bu. The calculator also shows the added peak-cone capacity and total weight in pounds, short tons, and metric tonnes.
Formula
How this is calculated
A standard grain bin is a steel cylinder with a conical roof. The storage capacity has two parts: the cylindrical volume below the eave (straightwall height) and the peaked cone above it. The cylinder volume is the standard formula π/4 × D² × H, where D is the inside diameter and H is the eave height in feet.
To convert cubic feet to bushels, the cubic volume is multiplied by the grain's bulk density (lbs/ft³) and divided by its test weight (lbs/bushel) — the USDA standard values used here are: corn 44.8 lb/ft³ / 56 lb/bu, soybeans 47.6/60, wheat 48.0/60, barley 38.4/48, oats 26.4/32, sorghum and rye 44.8/56. These are dry-grain values; wet grain has a higher density and lower effective bushel count, so always dry grain before filling a bin.
The peak capacity adds a cone with a height estimated from a 35-degree angle of repose (typical for most grains). In practice, some grain is always lost in the transition between the cone and the flat floor, and moisture, grain condition, and airspace all reduce usable capacity. Treat the peak figure as an upper estimate.
Frequently asked questions
The calculator uses USDA average bulk densities for dry grain at standard moisture content (corn: 15.5%, soybeans: 13%, wheat: 13.5%). Grain at higher moisture is heavier per bushel, so scale weights will be higher. At lower moisture, it may be slightly lighter. The bushel count remains the same because the test weight adjusts proportionally.
The cone adds roughly 5–8% of capacity depending on diameter and angle of repose, but it's difficult to fill uniformly, hard to aerate, and can create quality problems. Many operators plan around the straight-wall (cylinder) capacity and treat the cone as a safety buffer.
The calculator uses US feet and USDA bushels, which are the standard units for North American grain storage. To convert: 1 metre = 3.2808 ft, so a 10 m diameter bin is 32.8 ft diameter. Enter the foot-equivalent values in the fields.
Also known as
TG we-Calculate Editorial Team. (2026). Grain Bin Calculator — Bushel Capacity & Weight [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/grain-bin-calculator
TG we-Calculate Editorial Team. "Grain Bin Calculator — Bushel Capacity & Weight." TG we-Calculate. 2026. https://we-calculate.com/calculator/grain-bin-calculator.
TG we-Calculate Editorial Team, "Grain Bin Calculator — Bushel Capacity & Weight," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/grain-bin-calculator
@misc{wecalculate_grain_bin_calculator, title = {Grain Bin Calculator — Bushel Capacity & Weight}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/grain-bin-calculator}}, year = {2026}, note = {TG we-Calculate} }
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