Silage Pile Calculator
Estimate how much forage a bunker or pile holds, in as-fed and dry-matter tons.
Results
How to Use This Calculator
Enter the required input values in the form fields above. Each field includes default values that you can adjust to match your specific situation. Click the Calculate button (or simply change any input) to see instant results. Use the Metric/Imperial toggle to switch between unit systems. Results are displayed in the results panel and can be used for farm planning and decision-making.
About This Tool
This calculator is designed to help farmers, agronomists, and agricultural students make quick, accurate calculations for farm management. It uses standard agricultural formulas based on extension service recommendations and scientific literature. Whether you are planning inputs, estimating yields, or managing finances, this tool provides reliable estimates to support your decisions.
Applicability: This calculator is designed for global livestock operations, with particular relevance for North American and European cattle, pig, and poultry farms.
How the Calculation Works
For a trapezoidal pile, Volume (cu ft) ≈ length × width × height ÷ 2. Weight (lb) = volume × packed density. As-fed tons = weight ÷ 2,000. Dry matter tons = as-fed tons × (100 − moisture %) ÷ 100. Typical packed densities: 35–45 lb/cu ft for corn silage at 65% moisture.
Real-World Example
100 ft × 30 ft × 12 ft pile, 40 lb/cu ft, 65% moisture: volume = 18,000 cu ft. Weight = 720,000 lb = 360 as-fed tons. Dry matter = 360 × 0.35 = 126 tons DM.
Common Mistakes & Tips
Common mistakes: using loose (not packed) density; forgetting the ÷2 trapezoid factor; ignoring that pile sloping reduces true volume; confusing as-fed with dry-matter tons. Pack carefully and sample moisture for accuracy.
Reviewed by Agricalc Editorial Team — Agricultural engineers and agronomists with 10+ years of field experience. Our team verifies every calculator formula against peer-reviewed extension publications. For site-specific advice, consult your local agronomist.
References
- Penn State Extension — Bunker Silo Management
- USDA ARS — Silage Production & Storage
- FAO — Silage & Forage Guidelines
Frequently Asked Questions
What is a typical silage density?
Well-packed corn silage ranges 35–45 lb/cu ft (as-fed). Good packing with enough tractor weight on the pile reaches 40+; poorly packed piles can be 25–30 lb/cu ft and spoil faster.
Why divide volume by 2?
A pile has a triangular/trapezoidal cross-section, not a rectangular box. The ÷2 approximates the sloped sides. For a flat-top bunker silo with vertical walls, use full L×W×H instead.
What moisture should corn silage be?
Ideal harvest moisture is 60–65% for bunkers, 65–70% for bags. Too wet causes seepage and clostridial fermentation; too dry causes heating and molding.
What is dry matter (DM)?
Dry matter is what remains after water is removed. At 65% moisture, DM = 35%. Rations are balanced on DM, not as-fed weight, because water content varies.
How do I improve packing density?
Thin layers (6 inches), continuous packing with heavy tractors, fill in wedge shape, pack along the edges repeatedly, and seal within hours. Density directly determines spoilage and feed quality.
