Grain Bin Calculator

Estimate how many bushels of grain a cylindrical bin holds.

How the Math Works

The Grain Bin Calculator uses the formula bushels = π r² h ÷ 1.244 to determine storage capacity. This calculation starts with the standard cylinder volume formula (πr²h), where π (pi) equals approximately 3.14159, r is the radius of the bin, and h is the height. The result gives volume in cubic feet. To convert cubic feet to bushels (a standard agricultural measurement), we divide by 1.244, which represents the number of cubic feet in one bushel of grain. This conversion factor accounts for the specific density and packing characteristics of grain.

Practical Applications

To use this calculator practically, first measure your grain bin's diameter at its widest point and divide by 2 to get the radius. Next, measure the vertical height from bottom to top. Enter these measurements into the calculator with the radius squared (r²), multiplied by pi (π), then by the height (h), and finally divided by 1.244. For example, a bin 10 feet in diameter (5 ft radius) and 12 feet tall would calculate as: 3.14159 × 25 × 12 ÷ 1.244 = 754 bushels of capacity. This helps you plan storage needs before harvest season begins.

Day-to-Day Use

Knowing your grain bin's exact capacity helps farmers and grain handlers make informed decisions throughout the growing season. Before harvest, you can calculate how much grain your bin can hold to determine if you need additional storage or can safely store your current crop. During harvest, this information helps track how full your bin is becoming and when to pause harvesting to prevent overflow. Beyond harvest timing, the calculation aids in pricing decisions, as knowing your storage capacity helps determine optimal selling quantities and timing based on market conditions, ultimately improving profitability for your farm operation.

Worked example

18 ft diameter, 16 ft grain → ~3,273 bushels.

FAQ