Crop Yield Estimate Calculator
Estimate corn grain yield in bushels per acre before harvest using the yield-component method — ear count, kernels per ear and kernel weight.
How it works
Yield (bu/acre) = (ears/acre × kernels/ear) ÷ kernels per bushel
The yield-component method builds a grain estimate from what you can count in the field: how many ears stand per acre and how many kernels each carries. Dividing total kernels by a kernels-per-bushel factor converts kernel count into bushels, since a bushel of corn is a fairly consistent number of kernels. The kernels-per-bushel factor is the big unknown — use a lower number in a good year with heavy kernels and a higher one when late stress shrinks them.
Worked example
A stand of 30,000 ears/acre averaging 16 rows × 30 kernels = 480 kernels per ear gives 14,400,000 kernels/acre. At 90,000 kernels per bushel, that is 14,400,000 ÷ 90,000 = 160 bu/acre.
Frequently asked questions
When should I take the estimate?
Once kernels are dented and the stand is set, usually late in grain fill. Earlier estimates are shakier because kernel abortion and final kernel weight are not yet locked in. Sample several representative spots and average them.
What kernels-per-bushel number should I pick?
A common default is 90,000. Use around 85,000 in high-yield, well-finished fields where kernels are large and heavy, and up to 95,000 or more when drought or late-season stress produces smaller kernels.
Does this work for wheat or soybeans?
The same component logic applies — heads per acre × kernels per head ÷ kernels per bushel for wheat, or pods × seeds ÷ seeds per bushel for soybeans — but the factors differ. This tool is calibrated for corn defaults, so change the inputs accordingly.
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This calculator is for educational purposes. Double-check important results before acting on them.