Turn bunker length × width × average packed depth and as-fed density into wet tons — with optional dry-matter tons from DM %.
Use this when you need a first-pass inventory of corn silage (or similar) in a rectangular bunker or drive-over pile approximated as a box.
Extension often cites ~14 lb DM/ft³ well-packed bunker density; at 35% DM that is about 40 lb as-fed/ft³. Adjust density for packing quality.
Volume times density gives pounds; divide by 2,000 for wet tons. DM tons = wet tons × (DM% ÷ 100).
ft³ = L × W × depth
wet_tons = ft³ × density_lb_ft3 ÷ 2,000
dm_tons = wet_tons × (DM% ÷ 100)
If you know DM density instead: wet density ≈ DM_lb_ft3 ÷ (DM% ÷ 100).
Bunker 50 × 30 × 12 ft at 40 lb/ft³ as-fed, 35% DM:
Volume = 18,000 ft³ → 720,000 lb = 360 wet tons → DM ≈ 126 tons.
Assumptions: rectangular face; average depth accounts for sloping faces; density is uniform.
Limits: does not model wedges, feed-out faces, or spoilage. Drive-over piles are often less dense than walled bunkers.
Responsibility: verify with scales or Extension density probes for contracts and insurance.
Common planning default: ~14 lb DM/ft³ ÷ 0.35 DM ≈ 40 lb as-fed/ft³. Poor packing may be far lower.
Use average packed forage depth, not empty wall height, if the pile does not fill the walls.
Same volume math — change density and DM % to match your forage analysis.