1,546.04 US short tons of dry matter is the estimate for a 3-wall bunk 60 feet wide, 310 feet long and 12 feet high, with the front end open at a 3:1 slope and density at 15 lb DM/ft³. At 35% dry matter, that becomes about 4,417 as-fed tons. Those two weights describe the same feed. One includes its water; the other removes water from the accounting. Start with the units before deciding whether your storage is enough for the coming feeding period.
Choose the shape that matches the feed
Choose among four storage types: Trapezoidal Pile, Rounded Pile, 2-Wall Bunk and 3-Wall Bunk. Piles slope on every side. A 2-wall bunk has two opposite open ends; a 3-wall bunk has one. The example uses a 3-wall bunk with its front end open. Choose the arrangement that describes your filled storage before comparing weights.
Enter length, width and requested height. For a sloped structure, choose a horizontal-to-vertical slope ratio and use the open-side control where available. Inspect the 3D view to check the orientation. If the requested height cannot fit the selected dimensions and slope, the calculator displays an effective height and uses it for the estimate. Keep both heights in your record so the result is not mistaken for a full-height measurement.
The estimate assumes a flat rectangular footprint. It does not account for a sloping floor, irregular boundaries or feed crowned above bunk walls. Use filled dimensions, not unused pavement or the outside dimensions of concrete. When storage is too irregular for these choices, obtain a measured inventory. The white cover, tires and concrete walls help you recognize the selected shape. They do not add to the silage volume or measure your actual feed.
Separate volume, density and moisture
University of Wisconsin Extension agricultural engineer Brian Holmes explains inventory as stored volume multiplied by density in Making a Feed Inventory (Holmes, 2012). This tool uses dry matter density throughout. Multiplying cubic feet by lb DM/ft³ gives pounds of dry matter; dividing by 2,000 gives US short tons. Dividing that answer by dry matter percentage expressed as a fraction gives as-fed tons.
Feet and meters are both available for dimensions. Switching units converts your current measurements. Every result includes both volume units, using exactly 0.028316846592 cubic meters per cubic foot. The weight outputs remain US short tons even when dimensions are entered in meters. They are not metric tonnes. A moisture test and a density estimate must describe the same stored crop if you want the two weight columns to agree with your records.
Treat a density preset as an assumption
The 14, 15, 16, 18 and 22 lb DM/ft³ presets let you compare scenarios. They are not measurements of your feed. Start at 15 lb DM/ft³ for a comparison, then replace the assumption with a value supported by your own weight and volume records. A higher preset increases the estimated inventory; it does not establish that more feed is present or that a particular loss rate will occur. The calculator applies no automatic loss deduction.
In Factors Affecting Bunker Silo Densities, Muck and Holmes measured 175 Wisconsin bunker silos and examined packing factors associated with density (Muck and Holmes, 2000). Their study supports checking how density was obtained instead of assigning one number to every storage. Compare the preset with weight and volume records for your own feed. Keep the date and method beside the value.
Turn the estimate into a feed decision
Use a clearly labeled planning example: a 500-cow herd allocated 20 lb of silage dry matter per cow daily would use 10,000 lb, or 5 dry matter tons, each day. The example bunker would cover about 129 days before any allowance for losses. This is arithmetic, not a recommended ration. Your nutritionist should supply the allocation and your inventory records should supply the allowance.
For a budget, divide the actual daily silage cost by the number of cows to express it in $/cow/day. Divide daily cost by milk shipped in hundredweights to express it in $/cwt. Neither number can be inferred from pile dimensions alone. Keep prices, cow counts and milk output as separate dated inputs so a capacity estimate does not become an unsupported savings claim.
Read the bunker calculation example, compare pile geometry, or connect storage with corn silage yield per acre. Enter your filled dimensions above, choose a density you can support, and email yourself the PDF before your next feed planning meeting.