💧 Grain Moisture Calculator — Shrinkage & Weight Adjustment
Calculate grain shrinkage, adjusted weight, and moisture discount. Essential for harvest planning and grain deliveries.
Quick answer: Shrinkage % = (Initial % − Final %) × 1.2. 10 tonnes at 18% dried to 12% = 6% shrinkage → 9.4 tonnes. Standard delivery moisture: Wheat/barley 12%, Canola 8%.
💧 Calculate Grain Moisture Adjustment
—
Adjusted Weight (tonnes)
📐 How Grain Shrinkage Is Calculated
Shrinkage % = (Initial moisture % − Standard moisture %) × 1.2 (cereals)
Adjusted weight = Initial weight × (100 − Shrinkage %) ÷ 100
- Check current moisture — using a moisture tester at delivery point
- Know standard moisture — wheat 12%, canola 8%
- Calculate shrinkage factor — each 1% over standard costs 1.2% weight
- Calculate adjusted weight — this is what you get paid on
📊 Worked Example
100 tonnes of wheat at 16% moisture delivered. Standard moisture 12%.
Shrinkage = (16 − 12) × 1.2 = 4.8%
Weight lost = 100 × 4.8% = 4.8 tonnes
Adjusted weight = 100 − 4.8 = 95.2 tonnes
At $300/t, moisture cost = 4.8t × $300 = $1,440 penalty. Drying to 12% before delivery saves this cost.
❓ Frequently Asked Questions
Shrinkage % = (Initial moisture − Final moisture) × 1.2. Adjusted weight = Initial weight × (100 − Shrinkage %) ÷ 100. Example: 10 tonnes at 18% dried to 12% = 6% shrinkage → 9.4 tonnes.
Wheat/barley: 12%, Canola: 8%, Oats: 14%, Corn/maize: 15%. Higher moisture incurs discounts. Lower moisture is paid on adjusted weight.
Typical drying cost: $5-15 per tonne per 1% moisture removed using on-farm driers. Commercial drying charges $10-25 per tonne.
Calculate both options. Drying is often cheaper if you have on-farm capacity. Example: 200 tonnes at 16% moisture. Discount = $5/t × 4% = $20/t → $4,000 penalty. Drying cost = 200t × $12/t = $2,400 + shrinkage loss.