Silage Tonnage Calculator
A silage tonnage calculator estimates the weight of silage held in a bunker, pile or silo from its volume and the density of the packed material. Silage weight matters for feed planning, inventory and ration costing, but you cannot weigh a whole pile, so it is estimated from volume times density. This tool takes the storage volume in cubic feet and the silage density in pounds per cubic foot, multiplies them to get total pounds, then divides by 2,000 to convert to US tons. Both inputs are editable so you can model corn silage, haylage or any forage, at the packing density your storage achieves. Density depends heavily on moisture and how well the silage is packed, so a measured or published density for your crop and storage gives the most reliable result. Knowing the tonnage lets you plan how long the feed will last, value the inventory, and order what you still need. The US Geological Survey publishes the volume and area measurement data behind accurate storage sizing. Every figure is computed deterministically from the volume times density formula shown below, with a worked example that reconciles exactly to the calculator so you can follow each step yourself.
Silage tonnage multiplies volume by density, then converts to tons: tons = volume x density / 2,000. A 10,000 cu ft bunker at 40 lb per cu ft holds 200.00 tons of silage.
Silage tonnage formula
Tons = (V x D) / 2,000
V = storage volume (cubic feet)
D = silage density (pounds per cubic foot)
2,000 = pounds per US ton
Density varies with crop, moisture and packing. Corn silage often packs near 40 to 45 pounds per cubic foot as fed; use a measured value for the best estimate.
Worked example
A bunker holds 10,000 cubic feet of corn silage packed to 40 pounds per cubic foot.
- Volume = 10,000 cu ft, density = 40 lb/cu ft
- Total weight = 10,000 x 40 = 400,000 lb
- Tons = 400,000 / 2,000 = 200.00 tons
The bunker holds 200.00 tons of silage. These are the calculator's default inputs, so the result above matches the widget exactly.
Silage Tonnage Calculator: frequently asked questions
How do I find the silage volume?
For a rectangular bunker, multiply length by width by the average silage depth. For a drive-over pile, estimate it as a wedge or use the average end area method. For a tower silo, use the cylinder volume. The result is cubic feet, which this calculator multiplies by density.
What density should I use?
Density depends on the crop, its moisture and how well it is packed. Corn silage as fed often packs around 40 to 45 pounds per cubic foot, but yours may differ. A measured density from a core sample gives the most accurate tonnage. Higher packing density stores more feed in the same space.
Is the result as-fed or dry tons?
It is as-fed (wet) tons if you use an as-fed density, because the weight includes the water in the silage. To get dry matter tons, multiply the result by the silage's dry-matter fraction, or use a dry-matter density to begin with.
Why divide by 2,000?
There are 2,000 pounds in a US (short) ton. Volume times density gives pounds, so dividing by 2,000 converts to tons. If you work in metric, multiply volume by density in kilograms per cubic meter and divide by 1,000 for tonnes.
How long will the silage last?
Divide the total tons by the daily feed-out in tons, which is the number of animals times their daily silage intake. That gives the days of feed remaining, useful for planning purchases before the pile runs out.
Official sources
- Volume and area measurement data: US Geological Survey (USGS). As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.