Corn Yield Estimator
Estimate your harvest potential using the Yield Component Method.
How to Estimate Corn Yield
The Corn Yield Calculator uses the "Yield Component Method," developed by the University of Illinois. This method is most accurate when used during the milk or dough stages (R3-R4) up to maturity. It relies on representative samples from your field to project the final volume of grain before the combines hit the field.
The Math Behind the Yield
To calculate yield, we determine the total number of kernels in an acre and divide that by the number of kernels it takes to fill a standard 56-lb bushel. The formula used by this tool is:
Yield (bu/ac) = (Plants/Acre × Ears/Plant × Kernel Rows × Kernels/Row) / Kernel Factor
Measuring Your Inputs
- Plants per Acre: Count the number of productive plants in 1/1000th of an acre (for 30-inch rows, this is 17 feet 5 inches). Multiply by 1,000 for your input.
- Rows per Ear: Pick representative ears and count the number of longitudinal rows. It is almost always an even number.
- Kernels per Row: Count the number of full kernels in a single row. Do not count the small kernels at the tip or the very butt of the ear.
- Kernel Weight Factor: This represents "test weight." In a good year with large kernels, use 75 or 85. In a stressed year with small kernels, use 100 or higher.
Real-World Example
If you have a stand count of 30,000 plants per acre, each bearing 1 ear, with an average of 16 rows per ear and 38 kernels per row, and you assume an average kernel size (90 factor):
(30,000 × 1 × 16 × 38) / 90,000 = 202.6 Bushels Per Acre.