Corn crib volume

Hi guys,
I am afraid this is going to get long, but here goes. I have 4 corn cribs that I need to find out how many bushel of cobbed corn they will hold. I then need to be able to convert the cobbed corn volume into how many bushels each have in shelled corn. I need to do this to figure out my yeild this fall for the insurance company. I am going to pick all of my corn and then shell it next spring.
Crib 1 is round 15ft 6in tall to roof by 12ft 6 across. It will have a 18in x 18in by 16ft long sqaure vent through the middle.

Crib 2 is round 12ft tall to roof by 12ft 2in across. Also a 18in x 18in by 12ft long sqaure vent through the middle

Crib 3 is the old wood pentagon shape type. Smaller at the bottom and wider at the top.
It is 14ft long. 6ft 2in wide at the bottom and 8ft wide at the top near roof line. It is 7ft 4 from floor to roof line.

Crib 4 is a small old wood pentagon shape type. Smaller at the bottom and wider at the top.
It is 15ft long. 4ft wide at the bottom and 5ft
6in wide at the top near roof line. It is 4ft 6 from floor to roof line.

I really appreciate the help with the volume. I know it is different from year to year, but I really need help converting cobbed bushels to shelled bushels for each crib.

Bottom of page one of my link gives you the formula.

Figure the cubic feet volume of your various cribs, and multiply by .4 to get bushels of ear corn.

For example, crib 4 is:

15 times 4.75 times 4.5 = 285 cubic feet.

285 times .4 = 114 bu ear corn

Paul
UofM corn volumes

Thanks Paul you have always been so helpful to me. I think we're both Minnesota'ins. I printed off the info. On the figuring you did, did you mean that the cubic feet you figured is actually equaling how many bushel of shelled corn and not ear corn. The way I figured using the U of M sheet is that the 114 you came up with is 114 bushel of shelled corn after the ear corn was shelled out. I am not good with math so I'm just tring to get an understanding of it. I understand that it takes 2.5 cu ft of ear corn to equal a bushel of shelled corn. Am I way off?

Bushel capacity for any grain is volume in cubic feet times point 8 equals bushels. Divide by 2 to get bushels of ear corn. Pentagon shape of the crib requires a bit more math to get cross section area. Draw lines to create trapezoids, triangles, etc, to determine area. Area times length equals volume.

My ultimate answer I am looking for is once each one of these cibs is full of ear corn, roughly how much will each translate in to shelled corn. I now understand how to figure the volume, but once I get there I have a brain block. I take the volume x .8 to get how much the crib would hold if it were full of shelled corn. Do I then divide that by 2.5 according to the U of M website?

No, you divide those bushels by 2, to get ear corn equivalent. Like paul says.....volume times point 4 gives you ear corn. Same as volume times point 8 gives you shelled corn, then divide by 2 to get ear corn. Ear vs shelled is a 1:2 ratio. The crib holds half as many bushels of ear corn as it does shelled corn.

Yup, we always measure in actual shell corn, a bu is supposed to be a volume measure, but actually we go by 56 lbs of shell corn, or 70 lbs of ear corn. The same bu of ear corn takes twice the volume as a bu of shelled corn.

There can be a pack or settle factor to ear corn, but different agencies have different versions of that..... If your corn has sat several months, they might allow as its packed tighter over time....

Paul