What is a typical packing density for corn silage?

Well-packed corn silage commonly targets at least 14–15 lb of dry matter per cubic foot. This is not as-fed density: at 35% dry matter, 15 lb DM/ft³ corresponds to about 42.9 lb as-fed/ft³. Use a measured core density when available.

What dry matter percentage should I enter?

Corn silage is usually ensiled at 30–38% dry matter (62–70% moisture). Haylage ranges from 35–60% DM. If unsure, use a forage moisture tester or send a sample to a lab.

How is drive-over pile volume calculated?

A drive-over pile is approximated as a semi-elliptical prism. Volume = 0.5 × π × (width/2) × peak height × length. Real piles are irregular, so use average dimensions and treat the result as an estimate.

Why does my bunker tonnage differ from what I expected?

Common causes are over-estimating packing density, not accounting for tapered walls, or using total wall height instead of average silage height. Measure the average silage face height for the most accurate result.

Can I use this for haylage or small grain silage?

Yes. Adjust dry matter density and dry matter percentage to match your crop. Keep the density input on a lb DM/ft³ basis; the volume math is otherwise the same.

Silage Tonnage Calculator

Enter storage dimensions, dry-matter density, dry matter percentage and optional shrink to estimate as-fed inventory and dry-matter tonnage.

Silage Storage Details

Silo Type

Length (ft)

Width (ft)

Height (ft)

Packing Density (lb DM/ft³)

Corn silage: 14–18 · Haylage: 10–14

Dry Matter (%)

Corn: 30–38 · Haylage: 35–60

Expected Shrink (%, optional)

Use 0 for gross stored inventory, or enter your own planning assumption.

Results

Enter dimensions and click Calculate.

Summary

Enter storage dimensions, dry-matter density, dry matter percentage and optional shrink to estimate as-fed inventory and dry-matter tonnage.

How it works

Select the silo type: bunker/trench, drive-over pile, or bag silo.
Enter the structure dimensions (length, width, height or diameter).
Set the dry matter packing density (lb DM/ft³) — a common minimum target is about 14–15 lb DM/ft³.
Enter the dry matter percentage and, if needed, an expected shrink percentage.
The calculator computes volume, as-fed US tons and metric tonnes, dry-matter tons, and usable inventory after shrink.

Use cases

Estimate feed inventory before winter to ensure adequate supply for the herd.
Verify that packing density meets recommendations during silage harvest.
Calculate dry matter tons for ration balancing and feed budgeting.
Compare storage capacity of bunkers vs. bag silos for a new facility.
Audit silage remaining at feed-out to track shrink losses.
Plan silage purchases or sales based on available storage tonnage.

Frequently Asked Questions

Last updated: 2026-09-26 · Reviewed by Nham Vu