Corn Yield Calculator

Related Calculators

1/1000 acre sample: A small measured area where you count harvestable ears, then multiply by 1000 to estimate ears per acre.

Harvestable ears: Ears likely to be picked by the combine and contribute to grain yield.

Kernel rows per ear: The number of rows that run around an ear. Count several ears and use an average.

Kernels per row: The number of kernels in one full row on an ear. This works with kernel rows to estimate total kernels on each ear.

Average kernels per ear: The calculator multiplies kernel rows per ear by kernels per row to estimate kernels on one ear.

Kernel fill assumption: The kernels-per-bushel value used to turn kernel counts into bushels. More kernels per bushel means smaller kernels and a lower yield estimate for the same ear counts [2].

Estimated yield: The result in bushels per acre, written as bu/acre.

Standard-moisture bushels: Corn yield expressed as 56 lb bushels at 15.5% moisture. Kernel-count methods estimate this directly; weighed harvested grain requires its measured moisture content for conversion.

Mistake: Entering every plant in Harvestable ears in the 1/1000 acre sample (count) even when some plants are barren or badly damaged.
Fix: Count only ears likely to make it into the combine so Harvestable ears per acre used in the estimate is realistic.

Mistake: Using both sampling methods at once by entering Harvestable ears in the 1/1000 acre sample (count) and expecting Plants per acre (plants/acre) to affect the answer too.
Fix: The calculator uses only the active method from What do you counted , so pick the right mode and ignore the hidden method.

Mistake: Counting kernels on one unusually big or small ear and typing that into Kernel rows per ear (rows) and Kernels per row (kernels) .
Fix: Average several representative ears so Average kernels per ear is not skewed by one outlier.

Mistake: Leaving the default Kernel fill assumption when field stress suggests smaller kernels, then treating Estimated yield as certain.
Fix: Try more than one kernel-fill option in Advanced to see how much the result changes.

Mistake: Typing the wrong area into Field size (acres) and then focusing only on Estimated total bushels for the field .
Fix: Recheck acreage first, because the whole-field total is just Estimated yield multiplied by field size.

Mistake: Applying harvest-moisture shrink to the kernel-count estimate a second time.
Fix: Use the counting-method result directly. Use "Weighed harvested grain" only to convert an actual net shelled-grain weight and measured moisture.

• This is an in-field estimate, not a guaranteed harvest result. Final yield can change with late-season stress, kernel depth, disease, lodging, and harvest loss.
• The calculator assumes the ears and kernel counts you enter are representative of the field. Uneven soils or variable stands can make one sample misleading.
• Kernel fill assumption strongly affects the answer. Choosing 80000, 90000, or 100000 kernels per bushel can shift the estimate a lot, especially in stressed crops.
• "Weighed harvested grain" requires net shelled-grain weight, its moisture content and the harvested acreage. The conversion excludes handling loss, dockage and drying charges; it is not a commercial settlement calculation.
• Only inputs shown for the active method are used. Counting methods ignore harvested grain weight and moisture. "Weighed harvested grain" ignores all ear counts, kernel counts and "Kernel fill assumption".
• Very low or very high results can be mathematically valid, but they often mean the counts were taken from a non-representative spot or entered with the wrong units.

How the calculator works

The two counting methods divide estimated kernels per acre by kernels per standard-moisture bushel. They already estimate 56 lb bushels at 15.5% moisture; applying harvest-moisture shrink again would understate yield [5]. The separate weighed-grain method conserves dry matter when converting measured shelled-grain weight to 15.5% moisture, then divides by 56 lb per bushel and harvested acreage [6].

kernels_per_ear = rows_per_ear x kernels_per_row

ears_per_acre = ears_sample x 1000

ears_per_acre = plants_per_acre x ears_per_plant

yield_bu_ac = (ears_per_acre x kernels_per_ear) / kernels_per_bushel

estimated_standard_bushels = yield_bu_ac x field_size_acres

weighed_standard_bushels = harvested_grain_lb x (100 - grain_moisture_percent) / 84.5 / 56

Mode logic

The counting methods use either sample ears times 1000, or plants per acre times ears per plant. "Weighed harvested grain" instead uses measured shelled-grain weight and moisture; divide its standard-moisture bushels by "Field size (acres)" for bu/acre. Hidden inputs do not affect calculations or validation.

Worked example

Suppose you count 28 harvestable ears in a 1/1000 acre sample, average 16 kernel rows per ear, and 34 kernels per row. With the average fill setting of 90000 kernels per bushel and a field size of 80 acres:

kernels_per_ear = 16 x 34 = 544

ears_per_acre = 28 x 1000 = 28000

yield_bu_ac = (28000 x 544) / 90000 = 169.24 bu/acre

estimated_standard_bushels = (28000 x 544 / 90000) x 80 = 13539.56 bu

The kernel-count estimate remains about 13,540 standard-moisture bushels; do not reduce it again for harvest moisture. Separately, 15,000 lb of weighed shelled grain at 22% moisture from 1.38 acres gives 247.25 bushels at 15.5% moisture, or 179.2 bu/acre [6].

How to interpret the main outputs

"Estimated yield" is the per-acre answer at 15.5% moisture. "Estimated total bushels for the field" covers the acreage entered on the same basis. Counting-method results depend on assumed kernel weight; weighed-grain results depend on measured weight, moisture and harvested acreage. The extra ear and kernel outputs appear only for counting methods.

Assumptions used here

The method assumes your ear counts represent the field and that the chosen kernels-per-bushel setting matches actual grain fill. Extension guides commonly show that results can vary noticeably from final harvested yield because kernel weight, late stress, and field variability are not fully known at sampling time [1][3][4].