# 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.

Questions?

Don Hofstrand, retired extension value added agriculture specialist, agdm@iastate.edu