Bushels = 0.628 × D² × H (for round bins)
Round grain bin capacity in bushels = π/4 × D² × H / 1.2445 ≈ 0.628 × D² × H (where 1 bushel = 1.2445 cubic feet). For peaked grain, add the cone volume: 0.209 × D² × peak height. A standard 24 ft × 18 ft bin holds about 6,500 bushels (flat) or ~7,000 with a 3-ft peak. One bushel of corn weighs 56 lbs; soybeans 60 lbs; wheat 60 lbs. Proper grain storage requires: moisture below 13-15% for long-term storage, adequate aeration, temperature monitoring, and regular inspection for insects and mold. Peaked grain is harder to aerate uniformly and should be leveled when possible.