Grain Bin Capacity Calculator

Estimate the bushels of grain in a round bin from its inside diameter and the depth of grain, using the standard 0.8036 bushels per cubic foot.

How it works

A round bin holds a cylinder of grain. The volume in cubic feet is the circle area times the grain depth, and each cubic foot of a level-full bin holds about 0.8036 bushels:

Bushels = ( π ÷ 4 × diameter² × depth ) × 0.8036

Measure the inside diameter and the actual depth of grain, not the height of the bin. This gives the capacity of the straight-sided part of the bin; a peaked or coned pile on top adds extra, and the exact bushel factor shifts slightly with how grain is defined, so treat the result as a close working estimate.

Why bushels

Grain in the US is bought, sold, and stored by the bushel, a volume measure that also corresponds to a standard test weight for each crop (for example 56 pounds for shelled corn and 60 pounds for soybeans and wheat). Knowing a bin's capacity helps you plan storage, track inventory through the marketing year, and load out the right amount. For contract or settlement quantities, rely on scale weights rather than a volume estimate.

This tool is a planning aid and does the math from the numbers you enter. It is not a substitute for a soil test, seed-tag information, or advice from your local Cooperative Extension office. Page updated Aug 4, 2026.