Corn Yield Calculator
From field counts to a clearer harvest estimate.
Field & Sample Inputs
Result
Estimated grain yield
199.1 bu/acre12.50 t/haField estimate · 1 sampling site
Kernel Fill Sensitivity
Higher kernels/bu means lighter kernels and a lower yield estimate.
Your Field Sampling Strip
Sample several representative sites. Kernel size, field variation and harvest losses affect actual yield.
Understanding the estimate
- Calculate kernels per acreEars × average rows × kernels/row × 1,000 for a 1/1000 acre sample.
- Convert to bushelsDivide kernels per acre by the assumed kernels per bushel.
Yield (bu/acre) = (ears × rows × kernels/row × 1,000) ÷ kernels/bu
- Adjust for moisture (weighed grain only)Adjusted mass = wet grain mass × (100 − harvest moisture) ÷ (100 − target moisture).
Sampling, bushel basis & assumptions
Sample representative sites away from end rows and average the site yields. At each site, estimate kernels per ear from several representative ears. Where ear sizes differ, use the mean of each ear's rows × kernels/row, rather than multiplying separate averages. You can enter that mean with rows = 1 and kernels/row = mean kernels/ear.
All sites use the selected sample area. Inputs are estimates, not a validated prediction interval. Small or biased samples may poorly represent a whole field. Kernel-count yields use an assumed market-weight kernel factor, so harvest-moisture correction is not applied again.
A standard corn weight bushel is 56 lb (25.40117272 kg). Kernels/bushel describes kernel mass and is different from measured test weight (lb per volumetric bushel). The 15.5% target in weighed-grain mode is editable; confirm the moisture basis required by your buyer. Water removal is modeled; handling losses, dockage and drying charges are excluded.
1 acre = 4,046.8564224 m²; 1 hectare = 10,000 m²; 1 decare = 1,000 m². Tonnes are metric (1,000 kg).
Frequently asked questions
How long is my sample strip?
Divide the ground sample area by row spacing. For 1/1000 acre and 30-inch rows: 43.56 ft² ÷ 2.5 ft = 17.424 ft. A 1/1000 hectare sample is 10 m², a different ground area; the calculator scales the yield accordingly.
Can I use hectares or decares?
Yes. Field area accepts acres, hectares, decares or m²; changing its unit preserves the physical area. Imperial/Metric changes row-spacing and grain-mass units. Results show both bu/acre and t/ha.
When should I correct moisture?
Use Weighed grain + moisture when you have harvested, shelled grain mass from a known ground area and measured its moisture. Do not enter whole-ear mass. Kernel counting already assumes a final kernel weight; applying a second harvest-moisture factor would be misleading.
Why does kernel fill change the estimate?
More kernels per 56-lb bushel means lighter kernels and fewer bushels for the same kernel count. The presets are editable scenarios, not universal seasonal recommendations. Compare several factors and sample several field locations.
About this calculator
Field-yield estimates are sampling approximations; moisture, kernel weight, field variability, and harvest loss affect actual yield.
Sources & References
Purdue ExtensionYield component methodCorn yield estimation and sampling guidance.
Iowa State University ExtensionKernel weight & samplingGrain weight, kernel counts and yield estimation methods.
USDA NASSCrop production dataCrop production statistics and yield information.Planning estimate, not a measured harvest or a guaranteed yield. Source logos identify references, not endorsement. Moisture mass-balance guidance.
From field counts to a clearer harvest estimate.