Grain Moisture Calculator
Calculate moisture-adjusted yield for corn, soybeans, wheat, and other grains. Convert wet yield to standard moisture instantly.
Calculator Inputs
Enter your field measurements
Harvestable ear count
Kernel rows around
Length-wise count
Standard: 15.5%
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 the Grain Moisture Calculator?
A grain moisture calculator adjusts wet-yield grain to standard moisture for any crop. Each grain has a different standard moisture level: corn 15.5%, soybeans 13%, wheat 13.5%, oats 14%, barley 14.5%, sorghum 14%. This calculator handles all of them with one simple interface. Moisture adjustment is essential because grain is bought, sold, and stored at standard moisture. If you harvest 200 bu of corn at 25% moisture, you actually have only about 181 bushels at the standard 15.5% moisture — a 9.5% shrink. This calculator does the math instantly and accurately. Use it for record-keeping, marketing decisions, and comparing yields across years.
Formula & Method
Adjusted yield = Wet yield × (100 − Actual moisture) ÷ (100 − Standard moisture). Standard moisture: corn 15.5%, soybeans 13%, wheat 13.5%, oats 14%, barley 14.5%, sorghum 14%. Example: 220 bu corn at 22.5% moisture adjusted to 15.5% = 220 × 77.5 ÷ 84.5 = 201.8 bu.
How to Use This Calculator
Using this calculator is simple. Just enter your field measurements in the form above:
- Ears per acre — count harvestable ears in 1/1000 acre of row (17'5" for 30" rows) and multiply by 1,000.
- Kernel rows per ear — average across 5 representative ears. Almost always an even number (14, 16, 18).
- Kernels per row — average across the same 5 ears, counting from base to tip.
- Grain moisture — use a moisture tester. If unknown, enter 15.5% (the standard).
Click "Calculate" and you'll see your estimated yield in bushels per acre, instantly adjusted for moisture. Take multiple samples from different field areas and average the results for best accuracy.
Tips for Accurate Yield Estimation
Right Timing
Estimate at R5-R6 stage for most accurate results. Kernel weight has stabilized.
Multiple Samples
Take 5-10 samples per field from different areas. Average for accuracy.
Representative Ears
Pick average ears — not the biggest or smallest. Avoid border rows.
Accurate Moisture
Test moisture with calibrated meter. Errors here propagate through calculation.
Frequently Asked Questions
Everything you need to know about corn yield calculation
This calculator is accurate within ±10% of actual harvest yield when used correctly. For best results, take 5-10 samples from different field areas, use representative ears (not the biggest or smallest), and apply the correct moisture adjustment. The closer to harvest you estimate, the more accurate the prediction.
Yes, completely free. No sign-up, no download, no cost. Use it as often as you need on any device — desktop, tablet, or smartphone. Works in the field even with limited internet connection.
The best time to estimate corn yield is at the R5 (dent stage) or R6 (physiological maturity) growth stage. At this point, kernel weight has stabilized and moisture levels are predictable. Estimating earlier (during R3-R4) is less accurate because kernels can still abort under stress.
Yes, this calculator is fully mobile-responsive. It works on any smartphone, tablet, or desktop. The interface adapts to your screen size for easy use in the field. Add it to your home screen for quick access during scouting.
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