Corn Ear Count Calculator
Estimate corn yield using the ear weight method. Weigh representative ears and calculate bushels per acre based on actual ear weight.
Ear Weight Method Inputs
Alternative yield estimation method
Weigh 5+ ears and average
From plant population
Field moisture
Take multiple samples from different field locations and average them for the most accurate results. Avoid border rows and unusual spots.
All calculations use USDA-standard formulas. No registration required, works on mobile, tablet, and desktop.
What Is a Corn Ear Count Calculator?
A corn ear count calculator estimates yield using the ear weight method — an alternative to the kernel count method that works well for corn at higher moisture or when you have a scale available. By weighing actual ears, this method can be more accurate than kernel counting, especially for corn with unusual kernel sizes or stressed growing conditions.
The ear weight method requires more equipment (a scale) but less counting. You harvest 5-10 representative ears, weigh them, and calculate yield from average ear weight, ear count per acre, and moisture content. This method is especially useful for silage corn or for verifying kernel-count estimates.
Many agronomists recommend using both methods and averaging the results. The kernel count method works well in dry, mature corn; the ear weight method is better for wetter corn at 25-35% moisture.
Ear Weight Yield Formula
The formula:
Yield (bu/ac) = (Ears/ac × Ear wt lb) × (100 − moisture) ÷ (84.5 × 56)
Where:
- Ears per acre = plant population × harvestable ear %
- Ear weight (lb) = average weight per ear
- 84.5 = 100 − 15.5 (standard moisture)
- 56 = pounds per bushel at standard moisture
Example
32,000 ears/ac, 0.5 lb/ear average, 22% moisture:
(32,000 × 0.5) × (100 − 22) ÷ (84.5 × 56) = 16,000 × 78 ÷ 4,732 = 263.6 bu/ac
This wet-yield estimate would shrink to about 220 bu/ac at 15.5% standard moisture.
Ear Count vs Ear Weight Method
Kernel Count Method
Count rows × kernels/row. No scale needed. Best for 15-25% moisture corn.
Ear Weight Method
Weigh representative ears. More accurate for wet corn. Requires scale.
Yield Monitor Method
Combine yield monitor data. Most accurate post-harvest. Calibrate regularly.
Satellite/Drone Method
NDVI imagery. Less accurate but scalable to thousands of acres.
Best Practices for Ear Sampling
- Sample at the right time: R5-R6 growth stage for best results.
- Take 5-10 samples from different field areas.
- Pick representative ears — not the biggest or smallest.
- Weigh immediately after harvest to prevent moisture loss.
- Account for non-harvestable ears — small ears with few kernels shouldn't be counted.
- Use accurate moisture — test grain moisture separately from cob.
Frequently Asked Questions
Everything you need to know about corn yield calculation
To count corn ears per acre, measure 1/1000 acre of row (17'5" for 30-inch rows). Count all harvestable ears (ears with at least some kernels) in that section. Multiply by 1,000 to get ears per acre. Take 5-10 samples from different field areas and average for best accuracy.
The ear weight method calculates yield by weighing representative ears rather than counting kernels. Formula: Yield = (Ears × ear weight) × (100 - moisture) ÷ (84.5 × 56). This method is more accurate than kernel counting for wet corn (over 25% moisture) but requires a scale.
A typical corn ear at harvest maturity weighs 0.4-0.7 pounds (180-320 grams) with husks removed. Excellent growing conditions can produce ears over 0.8 lb. Drought or stress can reduce ear weight to 0.2-0.3 lb. Average ear weight × ear count per acre determines yield.
The most accurate pre-harvest method is the ear weight method at R6 stage with proper moisture testing — typically within ±5% of actual yield. The kernel count method is accurate to ±10%. Combine yield monitors calibrated with scale tickets provide the most accurate post-harvest measurement.
Try Our Other Free Farm Calculators
Browse 30+ free agriculture tools trusted by farmers across the USA, Canada, and Australia.
See All Calculators