Silage Capacity Calculator
Calculate bunker, trench, tower, and bag silage storage capacity in wet tons, dry matter (DM) tons, cubic feet, and total herd feeding days.
Calculate Silage Bunker & Trench Storage Capacity
Enter structure length, width, wall height, packing density (lbs/cu.ft), moisture %, and daily herd feeding rate.
Calculation Results
Calculated using agricultural forage storage engineering standards: \text{Wet Tons} = \frac{\text{Volume (ft}^3\text{)} \times \text{Packing Density (lbs/ft}^3\text{)}}{2,000 \text{ lbs/ton}}
Quick Summary
The Silage Capacity Calculator evaluates storage volume ($\text{Wet Tons} = \frac{\text{Volume} \times \text{Density}}{2,000}$) in wet tons, dry matter tons, cubic yards, and herd feeding days for bunkers, silos, and bags.
Formula Explanation
\text{Storage Volume (ft}^3\text{)} = \text{Length (ft)} \times \text{Width (ft)} \times \text{Average Height (ft)}
\text{Wet Silage Capacity (short tons)} = \frac{\text{Storage Volume (ft}^3\text{)} \times \text{Packing Density (lbs/ft}^3\text{)}}{2,000 \text{ lbs/ton}}
\text{Dry Matter Capacity (DM tons)} = \text{Wet Tons} \times \left(\frac{100 - \text{Moisture \%}}{100}\right)How It Works
Silage preservation depends on rapid anaerobic fermentation achieved through heavy packing tractor compaction. The Silage Capacity Calculator multiplies bunker dimensions by fresh packing density (typically 40 to 45 lbs/cu.ft for corn silage), converting cubic storage space into wet tons and dry matter tons.
Step-by-Step Worked Example
Practical Problem: A dairy farmer fills a 120 ft long × 50 ft wide × 12 ft high bunker silo with corn silage packed to 42 lbs/cu.ft at 65% moisture. The herd eats 8,000 lbs of silage daily. Calculate wet tons, DM tons, and feeding days.
- Step 1: Bunker storage volume: $120 \times 50 \times 12 = \mathbf{72,000\text{ cubic feet}}$.
- Step 2: Total wet silage weight: $72,000\text{ ft}^3 \times 42\text{ lbs/ft}^3 = \mathbf{3,024,000\text{ lbs}}$.
- Step 3: Wet silage short tons: $3,024,000 / 2,000 = \mathbf{1,512.0\text{ short tons}}$ ($1,371.7\text{ metric tonnes}$).
- Step 4: Dry Matter (DM) tons (35% DM): $1,512.0 \times 0.35 = \mathbf{529.2\text{ DM tons}}$.
- Step 5: Herd feeding capacity days: $3,024,000 / 8,000\text{ lbs/day} = \mathbf{378\text{ days of silage supply}}$.
Real-World Calculation Examples
Scenario 1: 120' × 50' × 12' Bunker Silo
Parameters: 72k ft³, 42 lbs/ft³ density, 65% moisture
Result: 1,512 wet tons (529 DM tons, 378 days supply at 8k lbs/day).
Scenario 2: Commercial Silage Bag (10' × 250')
Parameters: 10' dia bag, 250' length, 45 lbs/ft³ density
Result: 442 wet tons (155 DM tons per 250 ft bag).
Scenario 3: Tower Silo (20' dia × 70' height)
Parameters: 20' dia tower, 70' height, 48 lbs/ft³ avg density
Result: 528 wet tons (185 DM tons tower capacity).
Scenario 4: Large Dairy Bunker (200' × 100' × 16')
Parameters: 320k ft³, 44 lbs/ft³ density, 65% moisture
Result: 7,040 wet tons (2,464 DM tons commercial storage).
Key Benefits of Using This Calculator
Bunker, Bag & Tower Support
Calculates storage capacity for horizontal bunker silos, ag bags, and upright tower silos.
Wet Weight & Dry Matter Dual Metrics
Displays total tonnage in both fresh wet weight and 100% Dry Matter (DM) equivalents.
Herd Feed Days Supply
Calculates exact days of silage inventory available for dairy cows or feedlot cattle.
100% Free & Client-Side
Executes locally in your browser with zero latency or web server transmission.
Frequently Asked Questions (FAQ)
What is ideal packing density for corn silage?
Target packing density is 40 to 45 lbs of fresh wet weight per cubic foot (15 to 16 lbs DM/cu.ft) to exclude oxygen and prevent mold growth.
What is ideal moisture content for bunker corn silage?
Ideal moisture for bunker silos is 65% to 70% (30% to 35% Dry Matter). Moisture above 70% causes seepage effluent loss; moisture below 60% impairs packing density.
How do I calculate bunker face removal rate to prevent spoilage?
Remove a minimum of 6 inches of silage face per day in winter and 12 inches per day in warm summer weather to prevent heating and spoilage.
How much does 1 cubic foot of corn silage weigh?
Fresh corn silage in a well-packed bunker weighs 40 to 46 lbs per cubic foot (1,080 to 1,242 lbs per cubic yard).
How much silage capacity is in a 10-foot diameter ag bag?
A 10-foot diameter ag bag holds approximately 1.7 to 1.8 wet tons of corn silage per linear foot of bag length.
Why is packing tractor weight important for bunker silos?
To achieve 45 lbs/cu.ft density, rule of thumb requires 800 lbs of packing tractor weight per ton of silage delivered per hour (e.g. 100 tons/hr delivery requires 80,000 lbs of tractor weight).
What is silage shrink loss percentage?
Silage shrink (fermentation, gas, and face spoilage loss) averages 10% to 15% in uncovered bunkers, 6% to 10% in covered oxygen-barrier bunkers, and 4% to 6% in ag bags.
What is the function of bacterial silage inoculants?
Homofermentative bacterial inoculants (e.g. Lactobacillus plantarum) rapidly drop silage pH below 4.2, preserving sugars and reducing DM shrink loss.
How do I convert short tons of silage to metric tonnes?
Multiply short tons by 0.907185 ($1,000\text{ short tons} = 907.2\text{ metric tonnes}$).
What is silage gas hazard in tower silos?
Nitrogen dioxide (NOâ‚‚) gas forms within 24 hours of filling tower silos. NOâ‚‚ is lethal; ventilate tower silos with blowers before entry!