A grain moisture correction calculator determines how much weight grain will lose when dried to standard storage moisture. Knowing shrinkage helps you evaluate elevator discounts, drying costs, and net grain value accurately. Enter your grain type, current moisture, and quantity to see corrected weight.
Grain Moisture & Shrinkage Calculator
From grain probe or combine yield monitor
Standard Moisture & Test Weights
| Grain | Std Moisture | lbs/bushel |
|---|---|---|
| Corn | 15.5% | 56 |
| Soybeans | 13.0% | 60 |
| Wheat | 13.5% | 60 |
| Oats | 14.0% | 32 |
| Barley | 13.5% | 48 |
How to Calculate Grain Moisture Shrinkage
When corn or soybeans are harvested at high moisture content, they must be dried to standard moisture for safe storage or sale. The drying process removes water — and the weight lost is called shrinkage. Understanding grain moisture correction is essential for accurately calculating your net grain inventory and profitability after drying costs.
The Shrinkage Formula
Shrinkage % = (wet MC% − dry MC%) ÷ (100 − dry MC%) × 100. For corn harvested at 22% moisture drying to 15.5%, shrinkage = (22−15.5)÷(100−15.5)×100 = 7.7%. That means for every 10,000 bushels of wet corn, you end up with about 9,230 dry bushels at standard moisture.
What Elevators Do
Grain elevators typically charge a drying fee per point of moisture plus a "shrink factor" (often 1.3–1.5% per point above standard). The shrink factor is higher than actual moisture shrinkage to cover grain handling losses. Compare elevator charges to on-farm drying costs to determine the most economical option for your operation.
Frequently Asked Questions
Is this grain moisture calculator free?
Yes, completely free. All calculations run locally in your browser.
What is the standard moisture for corn?
Standard storage moisture for corn is 15.5%. Corn above 15.5% must be dried before storage or sold at a discount. Elevators typically apply a shrinkage factor plus a handling charge for wet corn.
How do you calculate grain shrinkage?
Shrinkage % = (wet moisture% - dry moisture%) / (100 - dry moisture%) × 100. For example, corn at 25% moisture drying to 15.5%: (25-15.5)/(100-15.5) × 100 = 11.24% shrinkage.
What is standard moisture for soybeans and wheat?
Soybeans standard moisture is 13.0%. Winter wheat is 13.5%, spring wheat 13.5%. Oats are 14.0%. Grain above these standards is discounted; grain below may receive a premium at some elevators.
What is the cost of drying grain per point of moisture?
Natural gas-fired dryers typically cost $0.03–0.05 per bushel per point of moisture removed. Propane dryers run $0.05–0.08/bu/point. At 25% corn drying to 15.5%, that is 9.5 points × ~$0.04 = ~$0.38/bushel drying cost.