Corn Yield
Calculate corn yield per acre and total bushel production from a 1/1000 acre sample. Free corn yield estimator for farmers and agronomists with interactive charts.
About This Calculator
The Corn Yield Calculator helps farmers, agronomists, and crop consultants estimate corn grain yield before harvest using the standard 1/1000 acre sampling method. By counting ears and estimating kernels per ear from a representative sample, you can project the expected yield per acre and total bushel production for your field.
The calculation uses the widely-adopted corn yield formula: Yield (bu/ac) = (Kernels per Ear × Ears in Sample × 1000) ÷ Kernel Size Factor. The kernel size factor accounts for the number of kernels required to fill a bushel — 120,000 for small kernels typically associated with drought stress or late-season stress, 90,000 for medium kernels under normal conditions, and 80,000 for large kernels from optimal growing conditions. One bushel of corn weighs 56 pounds (25.4 kg).
For the sample measurement: in 30-inch row spacing, a 1/1000 acre sample equals 17 feet 5 inches of row. For 20-inch rows, use 26 feet 2 inches. Count all harvestable ears in the measured section, then shell and count kernels from a representative subset of ears to determine the average kernels per ear. The final estimate typically falls within ±10 bushels per acre of actual harvested yield when using proper sampling technique.
Key Formulas
Yield per Acre (bu/ac): (Kernels per Ear × Ears in 1/1000 ac Sample × 1000) ÷ Kernel Size Factor
Total Yield (bu): Yield per Acre × Field Size (acres)
Total Weight (lb): Total Yield (bu) × 56 lb/bu
Kernel Size Factors: Small = 120,000 kernels/bu, Medium = 90,000 kernels/bu, Large = 80,000 kernels/bu
Regional Notes
United States: The calculator uses bushels (bu) and acres as standard US agricultural units. The 1/1000 acre sampling method is widely recommended by US extension services. Typical US corn yields range from 150-200 bu/ac in the Corn Belt. Current market prices range from $3-5 per bushel depending on season and location.
India: While Indian farmers typically measure land in hectares and production in quintals or metric tons, the bushel-per-acre system is standard for corn yield estimation globally. For conversion: 1 bu/ac ≈ 67.3 kg/ha, 1 bushel = 25.4 kg. Consult your local agricultural extension office for region-specific corn yield data and recommended hybrids.
United Kingdom: UK farmers use tonnes per hectare for corn (maize) yield measurement. For reference: 1 bu/ac ≈ 0.0673 tonnes/ha, so 150 bu/ac ≈ 10.1 tonnes/ha. UK maize yields average 12-18 tonnes/ha for forage maize. Consult the AHDB for UK-specific maize growing recommendations.
Frequently Asked Questions
How is corn yield calculated?
Corn yield is calculated using the formula: yield (bu/ac) = (kernels per ear × ears in 1/1000 acre sample × 1000) ÷ kernel size factor, where kernel size factor depends on kernel size (120,000 for small, 90,000 for medium, 80,000 for large kernels per bushel).
What is a 1/1000 acre sample for corn yield estimation?
A 1/1000 acre sample is a standard method for estimating corn yield. In 30-inch row spacing, measure off 17 feet 5 inches of row length. Count all harvestable ears in that section and estimate average kernels per ear from a representative sample of ears.
How many kernels on an ear of corn?
One ear of corn contains approximately 800 kernels in 16 rows. To calculate kernels per ear, count the number of kernel rows around the ear and multiply by the number of kernels per row. Typical values range from 500 to 1,000 kernels per ear depending on hybrid and growing conditions.
What are the kernel size factors for corn yield estimation?
The standard kernel size factors used in corn yield estimation are: small kernels — 120,000 kernels per bushel, medium kernels — 90,000 kernels per bushel, and large kernels — 80,000 kernels per bushel. These factors account for the weight and volume of individual kernels.
How many ears of corn make a bushel?
Approximately 112 ears of corn make one bushel. An 8-inch ear of corn contains about 0.5 pounds of corn grain, and one bushel of corn weighs 56 pounds. This is a general estimate and actual ears per bushel varies with ear size and kernel weight.
What is the average corn yield per acre?
The average world corn yield is about 85 bushels per acre. In the United States, average yields reach 170-180 bushels per acre with modern hybrids and management. Corn yields have been increasing by 1.3-1.4% per year globally due to improved genetics and farming practices.
How much does a bushel of corn weigh?
One bushel of corn weighs 56 pounds (25.4 kg). This standard weight is used for corn trading and yield calculations globally. The price of corn has historically ranged from $3 to $4 per bushel in the past five years.
Can I use this calculator for other grains?
This calculator is specifically designed for corn using the standard 1/1000 acre sampling method. Other grains like wheat, soybeans, and sorghum use different sampling methods and conversion factors. Use our vegetable yield or grain bin calculators for related crop calculations.