Whole Farm > Weight & Measurements

## Storage Capacity for Grains, Forages and Liquids

### Terms

Diameter - distance across a round structure
Circumference - distance around a round structure
Pi - Constant with an approximate value of 3.1416
Density - pounds of grain, forage or liquid contained in one cubic foot of storage space

### 1. Round Grain Bin or Crib

Bushels = Pi x ½ diameter x ½ diameter x average depth of grain (all in feet) x density, or
Bushels = (½ circumference / Pi) x (½ circumference / Pi) x average depth of grain (all in feet) x Pi x density
Average depth of grain = height of grain on the outside wall of the bin plus one-third the height of the grain “cone” (from the top of the grain on the outside wall to the highest tip in the center)
Density = 0.8 bushels per cubic foot for corn or soybeans
Density = 0.628 bushels per cubic foot for ear corn
Short versions:
Bushels = 0.628 x diameter x diameter x average depth of grain (all in feet) for shelled corn or soybeans
Bushels = 0.314 x diameter x diameter x average depth of grain (all in feet) for ear corn

### 2. Rectangular Bin or Crib

Bushels = width x length x average depth of grain (all in feet) x density (same values as previous)

### 3. Upright Silo

Bushels = Pi x ½ diameter x ½ diameter x depth of grain (all in feet) x density x (1 - % moisture) / .845, for number 2 shelled corn or ground ear corn
Tons of dry matter = Pi x ½ diameter x ½ diameter x depth of (all in feet) x density / 2,000, for corn silage or haylage
Tons of wet silage or haylage = tons of dry matter / (1 - % moisture)
Density = 0.8 bushels per cubic foot for corn or soybeans
Density = 0.515 bushels per cubic foot for ground ear corn
Density = 8.0 + (0.15 x depth of silage) (in feet) = tons of dry matter per cubic foot for corn silage (density increases with the depth of the silage)
Density = 5.90 + (0.1 x depth of haylage) (in feet) = tons of dry matter per cubic foot for haylage (density increases with the depth of the haylage)
Short versions:
No. 2 Bushels = 0.7436 x diameter x diameter x average depth of grain (all in feet) x (1 - % moisture) for shelled corn
No. 2 Bushels = 0.4787 x diameter x diameter x average depth of grain (all in feet) x (1 - % moisture) for ground ear corn
Tons of dry matter = 0.000393 x diameter x diameter x average depth of silage (all in feet) x (8.0 + (0.15 x depth)) for corn silage
Tons of dry matter = 0.000393 x diameter x diameter x average depth of silage (all in feet) x (5.90 + (0.1 x depth)) for haylage
Tons of wet silage or haylage = tons of dry matter / (1 - % moisture)

### 4. Bunker (Trench) Silo

Tons of dry matter = Length x width x depth of corn silage (all in feet) x density / 2,000
Density = 7.5 + (0.4 x depth of silage) (in feet) = tons of dry matter per cubic foot for corn silage (density increases with the depth of the silage)
Density = 5.4 + (0.28 x depth of haylage) (in feet) = tons of dry matter per cubic foot for haylage (density increases with the depth of the haylage)
Tons of wet silage or haylage = tons of dry matter / (1 - % moisture)

### 5. Stack or Storage Shed, Small Square Bales

Tons = length x width x height (all in feet) x density / 2,000
Density = 6 to 8 pounds per cubic foot for hay
Density = 4 to 5 pounds per cubic foot for straw

### 6. Large Round Bales

Pounds = 3.1416 x (½ diameter / 12) x (½ diameter / 12) x (width / 12) (all in inches) x density
Density = 10 to 12 pounds per cubic foot for hay
Density = 5 to 7 pounds per cubic foot for straw
Density = 9 to11 pounds per cubic foot for corn stover
Short version:
Pounds = 0.0004545 x diameter x diameter x width (all in inches) x density

### 7. Large Square Bales

Pounds = (length / 12) x (width / 12) x (height / 12) (all in inches) x density
Density = 10 to 14 pounds per cubic foot for hay
Density = 6 to 8 pounds per cubic foot for straw
Density = 10 to 12 pounds per cubic foot for corn stover
Short version: Pounds = 0.0005787 x length x width x height (all in inches) x density

### 8. Water and Fuel Tanks

Cylindrical: Gallons = 3.1416 x ½ diameter x ½ diameter x length (all in feet) x 7.5 gallons per cubic foot
Rectangular: Gallons = length x width x height (all in feet) x 7.5 gallons per cubic foot
Weight = gallons x pounds per gallon
Weight = 8.33 pounds per gallon for water
Weight = 7.15 pounds per gallon for diesel fuel (at room temperature)
Weight = 6.15 pounds per gallon for gasoline

Reference: American Society of Agricultural and Biological Engineers Yearbook.

William Edwards, retired economist. Questions?
Don Hofstrand, retired extension value added agriculture specialist, agdm@iastate.edu