Grain Dockage Calculator
Quantify the weight and value lost to foreign material in your grain.
Results
How to Use This Calculator
Enter the required input values in the form fields above. Each field includes default values that you can adjust to match your specific situation. Click the Calculate button (or simply change any input) to see instant results. Use the Metric/Imperial toggle to switch between unit systems. Results are displayed in the results panel and can be used for farm planning and decision-making.
About This Tool
This calculator is designed to help farmers, agronomists, and agricultural students make quick, accurate calculations for farm management. It uses standard agricultural formulas based on extension service recommendations and scientific literature. Whether you are planning inputs, estimating yields, or managing finances, this tool provides reliable estimates to support your decisions.
Applicability: Relevant for grain storage operations in North America and Europe.
How the Calculation Works
Dockage weight = total weight × dockage % ÷ 100. Net weight = total − dockage. Dockage bushels = dockage weight ÷ test weight. Economic loss = dockage bushels × deduction rate per bushel.
Real-World Example
50,000 lb at 3% dockage: dockage = 1,500 lb, net = 48,500 lb. At 56 lb/bu: 26.8 bu of dockage. At $0.10/bu deduction: $2.68 loss per load — small per load but adds up over a season.
Common Mistakes & Tips
Common mistakes: guessing dockage instead of sieving a sample; confusing dockage (foreign material) with moisture; applying the deduction to gross instead of net weight; not keeping a copy of the probe report.
Reviewed by Agricalc Editorial Team — Agricultural engineers and agronomists with 10+ years of field experience. Our team verifies every calculator formula against peer-reviewed extension publications. For site-specific advice, consult your local agronomist.
References
- USDA AMS — Grain Dockage & Grading
- UMN Extension — Grain Marketing & Dockage
- FAO — Grain Quality & Impurities
Frequently Asked Questions
What is dockage?
Dockage is foreign material — chaff, broken kernels, weed seeds, dirt, stems — mixed with the grain. Elevators remove and weigh it out before paying you for clean grain.
How is dockage measured?
A probe sample is sieved and separated; the foreign material is weighed as a percentage of the sample. Standard dockage is usually 1–2% for clean grain; 3%+ triggers discounts.
What raises dockage?
Weed seed pressure, combining too fast, open concave settings, worn screens, harvest weeds before they shatter, and grain comingles with chaff. Adjust combine settings and sample loads.
Is dockage the same as moisture?
No. Dockage is physical foreign material; moisture is water in the grain. Both can reduce what you are paid, but they are deducted by different mechanisms.
Can I challenge a dockage charge?
Yes. Keep a duplicate probe sample sealed and dated. If you disagree, request a re-check or use a licensed grader. Some states have grain inspection dispute processes.
