Corn Grain Yield Calculator
Estimate saleable grain bushels — not just field bushels — and see how moisture and drying cost change the number that actually hits your settlement sheet.
Corn Yield Calculator
Enter measurements and your actual grain moisture to see saleable bushels
Harvestable ear count
Kernel rows around
Length-wise count
Standard: 15.5%
Use "Average of multiple" for accuracy
Elevators charge roughly 1.4%% shrink per point of moisture above 15.5%%. Harvesting at 25%% instead of 20%% costs you about 7%% of your bushels to shrink — on 200 bu/ac that's 14 bushels gone, or $63 at $4.50 corn.
Propane drying burns about 0.02 gallons per bushel per point of moisture removed. Taking 25%% corn down to 15.5%% on 200 bu/ac uses ~38 gallons of propane per acre — budget for it.
Field Bushels vs. Saleable Bushels
The number the calculator returns — adjusted yield in bushels per acre — is your field yield converted to the 15.5 percent moisture standard. That's the number you'll see on the elevator settlement sheet, after shrink and drying. But between the field and the elevator, two things happen that cost you bushels: moisture above 15.5 percent gets shrunk, and propane gets burned to remove it. Understanding both is the difference between a yield estimate and a revenue estimate.
The moisture adjustment in the calculator already handles the weight conversion. Corn at 25 percent moisture weighs more than corn at 15.5 percent because of the extra water. The adjustment factor — (100 − your moisture) ÷ 84.5 — scales the raw count down to what the grain would weigh at the standard. So if the calculator says 195 bu/ac adjusted, that's already the saleable bushel figure, not the raw wet-weight figure.
The Shrink Factor
Elevators don't just convert weight to standard moisture — they also charge shrink, which accounts for the grain and dust lost in handling and drying. Typical shrink is about 1.4 percent per point of moisture above 15.5 percent, though it varies by elevator. Some use a flat factor; others use a formula that includes both water removal and a handling loss. If you harvest at 25 percent moisture, that's 9.5 points above standard, and shrink eats about 13 percent of your bushels (9.5 × 1.4%%). On a 200 bu/ac crop, that's 26 bushels per acre lost to shrink before drying cost is even counted.
The practical implication: every point of moisture you can let the corn dry down in the field saves you roughly 1.4 percent of your bushels plus drying cost. Letting corn drop from 25 percent to 20 percent in the field (if weather allows) saves about 7 percent of bushels plus propane. The trade-off is the risk of lodging, ear drop, and weather delay — but on balance, field drydown is usually the cheapest drying there is.
Drying Cost Economics
Propane drying burns about 0.02 gallons of propane per bushel per point of moisture removed. At 200 bu/ac and propane at $2.00/gallon, taking corn from 25 percent to 15.5 percent (9.5 points) costs: 200 × 9.5 × 0.02 × $2.00 = $76 per acre in propane alone. Add electricity for fans, labor, and equipment depreciation and the true drying cost approaches $100 per acre. That's why many growers aim to harvest at 20 percent or below when the season allows.
Putting It Together: A Decision Example
Suppose the calculator returns 200 bu/ac adjusted at 25 percent moisture. Saleable bushels after shrink: 200 × (1 − 0.014 × 9.5) = 200 × 0.867 = 173 bu/ac. Drying cost: ~$76/ac. Net revenue at $4.50 corn: 173 × $4.50 − $76 = $702/ac. If instead you wait a week and harvest at 20 percent: saleable bushels = 200 × (1 − 0.014 × 4.5) = 187 bu/ac. Drying cost: ~$36/ac. Net revenue: 187 × $4.50 − $36 = $806/ac. Waiting a week (if weather allows) is worth $104 per acre — a number that often justifies the risk of a small amount of lodging.
Frequently Asked Questions
Everything you need to know
Field yield is what's standing in the field. Saleable yield is what reaches the elevator after moisture shrink and drying losses. The calculator's adjusted yield already converts to 15.5% moisture, but shrink (typically 1.4% per point above 15.5%) and handling losses further reduce the final saleable bushels. Plan on saleable yield running 5-15% below field yield depending on harvest moisture.
Propane drying costs roughly $0.04 per bushel per point of moisture removed (at $2.00/gallon propane). At 200 bu/ac, removing 5 points of moisture costs about $40 per acre; removing 10 points costs about $80 per acre. Electricity, labor, and depreciation add another 20-30%. Field drydown is almost always cheaper when weather allows.
The optimal harvest moisture balances drying cost against lodging and ear-drop risk. Most growers target 20-25% moisture to capture the best of both: low enough that drying costs are manageable, high enough that stalks are still intact and ears stay on. Below 18% you risk ear drop and lodging losses; above 28% drying costs eat into profit.
The US standard moisture for #2 yellow corn is 15.5%. Elevators buy and price corn at this moisture. Wet corn (above 15.5%) is discounted for shrink and drying; dry corn (below 15.5%) is not given extra credit because the weight loss from water roughly offsets. The 15.5% standard is why the calculator adjusts all yields to that moisture.
Editorial Standards & Sources
All formulas and benchmarks on this page are based on the USDA Yield Component Method (Nielsen, R.L., Purdue University Extension) and USDA NASS crop production data. Our calculators are reviewed annually against the latest extension publications from Iowa State, University of Illinois, University of Nebraska, and Ohio State.
Methodology: The default 90,000-kernels-per-bushel divisor and the 15.5% moisture standard used throughout this site come directly from published USDA and land-grant extension guidance rather than an internal estimate. Where a figure is our own approximation — such as the ±10% accuracy range for the ear count method — we say so explicitly rather than presenting it as an official statistic.
Known limitations: Pre-harvest estimates from any ear-count-based calculator are a planning tool, not a substitute for actual combine yield-monitor data or elevator scale tickets. Accuracy depends heavily on how representative the field samples are; we recommend a minimum of five sample locations per field, as outlined in the sampling guidance on this page.
Content last reviewed for accuracy in August 2025. Have a correction or suggestion? Contact our editorial team — we respond to all substantive feedback within 5 business days.