Grain Moisture Shrinkage Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026Why shrinkage isn't just the moisture difference
Grain loses weight as water evaporates during drying, but the percentage weight loss is not simply the raw difference between initial and final moisture percentages - it must be calculated relative to the final dry weight basis.
Worked example
For grain drying from 20% to 15% moisture, starting at 1,000 units of weight:
Shrink % = ((20 - 15) / (100 - 15)) x 100 = 5.882% shrink (941.18 final weight)
Frequently asked questions
Why isn't shrinkage just 5% (the moisture point difference)? Because the same water removed represents a larger share of the lighter, drier final product - dividing by (100 - final moisture) rather than 100 correctly accounts for this, which is why shrinkage always comes out somewhat higher than the raw point difference.
Why does this matter for grain sales? Grain elevators apply shrinkage calculations (sometimes with additional shrink factors beyond pure moisture) to determine how much dry-basis grain weight a wet delivery actually represents, directly affecting payment.