Corn Yield Calculator

How to use this corn yield calculator

What this calculator does

This calculator converts a representative 1/1000-acre corn sample into an estimated grain yield in bushels per acre and total bushels for the selected field. It uses ear count, average harvestable kernels per ear, field area, and a kernel-weight assumption. The result is a pre-harvest planning estimate, not a scale-ticket measurement and not a guarantee of final harvested yield. Weather, disease, standability, harvest loss, moisture, test weight, and sampling bias can all move the realized result.

When to use it

Use it while scouting near or after kernel fill to compare fields, estimate storage and hauling needs, prepare a rough grain-marketing range, or test how smaller versus larger kernels affect expected production. For a more defensible estimate, repeat the sample in several representative areas and compare the results rather than relying on one unusually strong or weak spot. Iowa State University Extension provides practical guidance on collecting ears and counting harvestable kernels for yield estimates.

How to calculate

1. Count harvestable ears in a row length equal to 1/1000 acre for your row spacing, then enter that count under Ears in a sample.
2. Choose representative ears, count complete kernel rows and harvestable kernels per row, and enter the average under Kernels per ear.
3. Enter Size of the field and choose acres or hectares. The unit selector converts the current area instead of merely relabeling it.
4. Select Size of the kernels: small uses 120,000 kernels per bushel, medium 90,000, and large 80,000. Smaller kernels require more kernels to make a bushel and therefore reduce the bushel estimate.
5. Optionally expand Profit estimate, enter Corn price per bushel and Production cost per acre, then read gross revenue and estimated margin.
6. Review the kernel-size comparison table. Use Download Excel to save the current inputs, outputs, and comparison; use Reset to restore the documented defaults.

Input guide

Kernels per ear is required, accepts a plain positive number, and represents the average harvestable kernels on one sampled ear. A realistic example is 600. Raising it increases yield proportionally. Do not include visibly aborted tip kernels. Ears in a sample is required and is the harvestable ear count from exactly 1/1000 acre; 30 is a realistic example. Using a different sample area without converting it is a common error. Size of the field is required, must be greater than zero, and accepts decimals in acres or hectares; 100 acres is the default example. Area unit changes the display and converts the entered area, while calculations use acres internally. Size of the kernels is required and sets kernels per 56-pound bushel. Purdue Extension explains why the traditional factor varies with kernel weight and commonly ranges from roughly 65,000 to 105,000 kernels per bushel under different grain-fill conditions in its discussion of kernel weight and pre-harvest yield estimation.

Corn price per bushel is optional but must be zero or positive; enter a decimal such as 4.50 USD/bu. It changes gross revenue and margin, not biological yield. Production cost per acre is also optional and nonnegative; enter your own full or partial cost basis, such as 650 USD/acre. It is multiplied by acres and subtracted from gross revenue. A zero cost produces a margin equal to gross revenue, so do not interpret that as net farm profit unless zero really is your chosen cost basis.

Output guide

Yield per acre is the primary estimate in bushels per acre. Total yield multiplies that estimate by field acres. Ears per acre is the sample ear count multiplied by 1,000. Gross revenue is total bushels times price per bushel. Estimated margin subtracts cost per acre times acres from gross revenue and may be negative. The three summary pills repeat the primary yield, total bushels, and active kernel assumption. The comparison table shows the same sample under small, medium, and large kernel assumptions; its columns report kernels per bushel, yield per acre, total yield, and gross revenue. These are estimates driven by your inputs, not agronomic recommendations.

Worked example

With 600 kernels per ear, 30 ears in a 1/1000-acre sample, a 100-acre field, medium kernels at 90,000 kernels per bushel, a price of $4.50/bu, and zero entered cost, the estimate is: (600 × 30 × 1,000) ÷ 90,000 = 200.00 bu/acre. Total yield is 200.00 × 100 = 20,000.00 bu. Gross revenue is 20,000 × $4.50 = $90,000.00, and estimated margin is also $90,000.00 because the example cost is zero. The medium row in the table shows those same values.