liminfoGrain Moisture Calculator
Free web tool: Grain Moisture Calculator
Moisture Content
Moisture Content
15.00%
Water Weight
150.0
Dry Matter
85.00%
Shrink Factor Calculator
Shrink (%)
5.33%
Adjusted Weight
946.7
Weight Loss
53.3
Grain Shrink Reference
| Grain | Market Moisture (%) | Shrink Factor |
|---|---|---|
| Corn | 15.5% | 1.183 |
| Wheat | 13.5% | 1.156 |
| Soybeans | 13% | 1.150 |
| Barley | 14.5% | 1.170 |
| Oats | 14% | 1.163 |
| Sorghum | 14% | 1.163 |
| Rice | 12.5% | 1.143 |
MC (%) = (Wet Weight - Dry Weight) / Wet Weight {'\u00D7'} 100. Shrink = (Current MC - Market MC) / (100 - Market MC).
About Grain Moisture Calculator
The Grain Moisture Calculator is a free, browser-based tool for agricultural producers, grain elevator operators, commodity traders, and agronomists who need to compute grain moisture content and shrinkage-adjusted weight. The tool has two functional sections: a moisture content calculator and a shrink factor calculator. In the moisture section, users enter the wet weight and dry weight of a grain sample; the calculator instantly returns moisture content (%), water weight, and dry matter percentage using the standard wet basis formula: MC (%) = (Wet Weight − Dry Weight) / Wet Weight × 100.
The shrink factor calculator addresses one of the most financially significant aspects of grain marketing: price dockage for excess moisture. When grain is delivered at a moisture content above the standard market moisture, elevators and buyers deduct for the weight that must be lost during drying. Users select the grain type (corn, wheat, soybeans, barley, oats, sorghum, or rice) and enter the current moisture percentage. The tool computes shrink percentage using the formula: Shrink (%) = (Current MC − Market MC) / (100 − Market MC) × 100, then calculates the dry matter weight, adjusted market weight, and actual weight loss.
The reference table embedded in the tool provides the standard market moisture percentages and shrink factors for all seven supported grains: corn (15.5% market moisture, shrink factor 1.183), wheat (13.5%, 1.156), soybeans (13.0%, 1.150), barley (14.5%, 1.170), oats (14.0%, 1.163), sorghum (14.0%, 1.163), and rice (12.5%, 1.143). These figures align with USDA and standard grain trade specifications. The shrink factor represents the multiplier needed to convert dry-weight bushels to market-weight bushels.
Key Features
- Moisture content calculation from wet and dry weight using the wet basis formula
- Displays moisture content (%), water weight, and dry matter percentage simultaneously
- Shrink factor calculator supporting 7 grain types: corn, wheat, soybeans, barley, oats, sorghum, rice
- Shrink percentage computed from current moisture vs. standard market moisture for selected grain
- Adjusted market weight calculation showing what the grain would weigh at market moisture
- Weight loss display showing exact units lost due to excess moisture above market standard
- Built-in reference table with market moisture (%) and shrink factors for all 7 supported grains
- 100% client-side processing — no grain weight or moisture data is sent to a server
Frequently Asked Questions
What is grain moisture content and why does it matter?
Grain moisture content (MC) is the percentage of total weight that is water. It matters because grain stored at high moisture is susceptible to mold, mycotoxin development, and spoilage. Buyers and elevators pay for dry matter, not water, so grain delivered above the standard market moisture is discounted — either through price reduction or weight dockage. Most grains must be dried to market moisture before long-term storage or sale.
How is moisture content calculated?
Using the wet basis formula: MC (%) = (Wet Weight − Dry Weight) / Wet Weight × 100. For example, if a 1,000 lb sample dries down to 850 lb: MC = (1000 − 850) / 1000 × 100 = 15%. Dry basis moisture (used in some laboratory contexts) is calculated differently: MC_dry = (Wet − Dry) / Dry × 100, but wet basis is the standard in commercial grain trade.
What is shrinkage and how is it calculated?
Shrinkage is the percentage of original weight lost when grain is dried from its current moisture to the market standard moisture. The formula is: Shrink (%) = (Current MC − Market MC) / (100 − Market MC) × 100. For example, corn at 20% moisture dried to 15.5% market moisture: Shrink = (20 − 15.5) / (100 − 15.5) × 100 = 4.5 / 84.5 × 100 ≈ 5.33%.
What are the standard market moisture levels for common grains?
USDA-aligned standard market moisture levels are: corn 15.5%, wheat 13.5%, soybeans 13.0%, barley 14.5%, oats 14.0%, sorghum 14.0%, rice 12.5%. These are the moisture levels at which grain is traded at full market weight. Grain delivered above these levels is typically docked in price or weight.
What is the shrink factor and how is it used?
The shrink factor is a multiplier used to convert the quantity of grain at market moisture from a given starting moisture. For corn, the shrink factor is 1.183, meaning for every point of moisture above the 15.5% market standard, corn loses approximately 1.183% of its weight. The adjusted weight = Dry Matter Weight / (1 − Market MC / 100). The shrink factor simplifies this calculation for practical use by grain handlers.
How is adjusted market weight calculated?
Adjusted Weight = Dry Matter Weight / (1 − Market MC / 100), where Dry Matter Weight = Wet Weight × (1 − Current MC / 100). This gives the weight the grain sample would have at the market standard moisture. Weight Loss = Wet Weight − Adjusted Weight. These figures directly correspond to the financial dockage for excess moisture.
Can this calculator be used for freshly harvested grain?
Yes. Freshly harvested grain often has moisture content of 18–25% or higher depending on crop, variety, and weather conditions. Enter the harvest sample's wet and dry weights (from a grain moisture meter or oven-dry test) and the tool will immediately show how much drying is needed and what the shrinkage-adjusted market weight will be.
Is the Grain Moisture Calculator free?
Yes — completely free with no account required and no usage limits. All calculations run in your browser. No grain weight or moisture data is uploaded to a server or stored anywhere.