How this instrument works
A bushel is legally a volume (2,150.42 cubic inches), not a weight, which is why the same word converts to a different number of pounds depending on the crop filling it. Grain trading needs a weight figure to actually price and transport a load, so USDA established standard test weights per bushel for each major grain — fixed legal weight-per-bushel figures used industry-wide for grading, trading and freight calculations, independent of the small natural variation any individual load might show on a scale.
Corn's standard test weight is 56 lb per bushel, while wheat and soybeans both use 60 lb per bushel — different crops landing on different figures because each was set based on that crop's typical bulk density at standard moisture content when the standards were established, not derived from a shared formula. Wheat and soybeans happen to share the same 60 lb figure, a coincidence of two separately set standards rather than any underlying connection between the two crops.
The conversion itself is simple once the right test weight is selected: bushels multiplied by the crop's standard weight per bushel gives total pounds. Getting the crop selection right matters more than the arithmetic — applying corn's 56 lb figure to a load of wheat, or vice versa, introduces a 7% error before any other calculation even begins, which is why this instrument requires picking a grain type rather than assuming one.
- Enter the number of bushels into Bushels.
- Select your crop from Grain type — Corn (56 lb/bu), Wheat (60 lb/bu), or Soybeans (60 lb/bu).
- Read the converted total from Weight (pounds) beneath it; it recalculates instantly when either field changes.
- Double-check your crop selection before relying on the result — wheat and soybeans share an identical 60 lb/bu figure, but corn's 56 lb/bu is meaningfully different and easy to mix up.
Worked example — 100 bushels of corn
Enter 100 into Bushels and select Corn — 56 lb/bu from Grain type. Weight (pounds) reads 5600.00: 100 bu x 56 lb/bu = 5,600 lb exactly, with no rounding since both the bushel count and the standard test weight are whole numbers.
Selecting Wheat — 60 lb/bu instead, with the same 100 bushels entered, would return 6,000 lb — a 400 lb difference for an identical bushel count, purely because wheat's standard test weight is 4 lb per bushel higher than corn's. That gap is the entire reason this instrument asks for a grain type before converting.
Questions
Why isn't a bushel just a fixed weight like a pound or kilogram?
Because a bushel is legally defined as a volume — 2,150.42 cubic inches — not a weight, so how much a bushel weighs depends entirely on how dense the material filling it is. Corn, wheat and soybeans all pack differently at their standard moisture content, which is why grain trading relies on a separate standard test weight per crop rather than one universal bushel-to-pound conversion.
Why do wheat and soybeans share the same 60 lb/bu figure?
It's a coincidence of two independently set standards rather than any shared property between the crops — USDA set wheat's standard test weight and soybeans' standard test weight separately, based on each crop's own typical bulk density, and both happened to land on 60 lb per bushel. Corn, set independently as well, landed on a different figure, 56 lb per bushel.
What happens if I select the wrong crop by mistake?
You'll get a weight that's off by exactly the ratio between the two crops' test weights — mixing up corn (56 lb/bu) and wheat or soybeans (60 lb/bu) introduces roughly a 7% error in the converted pounds. Since the formula has no way to detect a wrong crop selection, double-checking Grain type against your actual load before reading the result is the only safeguard.
Are these standard test weights the same as what my load actually weighs?
Not exactly — standard test weight is a fixed legal reference figure used for grading and trading, while an actual harvested load can weigh somewhat more or less per bushel depending on moisture, foreign material and variety. Grain elevators measure actual test weight with a scale and moisture tester at delivery; this instrument uses the fixed standard figure for a consistent, comparable conversion rather than a specific load's measured weight.
Does this cover every grain crop, or just these three?
Just corn, wheat and soybeans — the three options offered in the Grain type selector. Other grains (oats, barley, rye, sorghum) each carry their own separately defined standard test weight per bushel that isn't included in this instrument's options, so converting those would require the correct figure for that specific crop.