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Grain Warehouse Bureau
How to Measure Your Grain

How do I find the bushels my round bin will hold?

(Diameter) x (Diameter )x (Depth )x (0.7854) = (cubic feet) x ( 0.80385)= Standard Bushels

How about the peak in my round bin?

(Diameter) x ( Diameter) x ( 0.7854) x ( 0.80385) = bushels per foot

The height of the peak above the base divided by 3 and multiplied times the bushels per foot = Standard Bushels

If you can not determine the height of the peak. Divide the Diameter by 2 and multiply that times 0.4 for corn or 0.5 for soybeans. Divide that number by 3 and multiply that times the bushels per foot = Standard Bushels

How about my round bin which is pulled down into a cone in the center?

Find the bushels per foot the same as the peak above. Find the depth of the cone or use the rule of thumb given above and multiply two thirds of that number times the bushels per foot.

You can also take the depth at the side wall and add one third of the height of the cone up or subtract one third of the depth of the cone down. Then calculate the bushels as if the bin were level across.

The rule of thumb of 0.4 times the radius of a bin for corn or 0.5 times the radius of a bin for soybeans works for dry clean grain. If the grain is wet or has a lot of fines the peaks and valleys will be higher and deeper.

The test weight of the grain will affect the number of bushels. The directions given above result in Standard (Winchester) Bushels. Corn weighing more than 54 pounds and soybeans weighing more than 56 pounds per bushels will have more bushels than the standard and if they weigh less there will be less bushels. The Pack charts are too big to be placed here. If you need that degree of accuracy talk to your County Extension office.

My grain does not lay in nice regular figures. Try to break your bin down into several rectangles, triangles, or cones and calculate each and add up the totals. Good luck!


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Mailing Address: IDALS,  Wallace State Office Building,   502 E. 9th Street,  Des Moines, IA 50319:     PH: 515-281-5321
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