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Grain Moisture Shrink Calculator

A wet load gets lighter as water leaves it. Enter the weighed grain and its starting and target moisture to see the weight left after drying. Add a separate handling allowance only if your plan calls for one.

Start with the measured load

Use the net grain weight, after vehicle tare. Both moisture readings must be percentages of the grain's total weight.

kg

Measured weight before drying, without truck or container.

Changing units converts a valid weight entry.

Set the moisture change

These are wet-basis moisture percentages. Use the final moisture from your crop, storage or buyer plan.

%

Moisture measured in the load before drying.

%

Your chosen target; it cannot exceed starting moisture.

Optional separate handling loss

Leave zero for water-only drying. Use a separate flat allowance only when you know it; do not enter a buyer's combined shrink factor here.

%

A flat percent of the original load, after water shrink is calculated.

Weight remaining

An estimate from dry-matter balance and your optional handling allowance.

Estimated saleable grain weight

Enter the load weight and two moisture readings, then calculate.

This is a weight estimate, not a buyer settlement. Check the contract for its shrink schedule, foreign-material deductions, grade adjustments and drying charges. The calculator does not pick a safe final moisture.

The wet load and the sale load are different weights

You have a grain weight from the scale and a moisture reading from the sample. Before drying, part of that weight is water that will leave the load. If you are planning transport, inventory or a sale, you need the grain's likely weight at the moisture you intend to reach.

This calculator follows the part that stays: dry matter. It then shows how much water leaves and, if you enter one, a separate handling allowance. You choose the final moisture from your crop, storage or buyer plan; the calculator does not supply a universal target.

How to use the calculator

Step 1

Enter the grain, not the truck

Use the net grain weight before drying. Choose kg, metric tonnes, lb or US short tons. If you switch units, a valid weight entry is converted for you. Do not include the vehicle or an empty container in the starting weight.

Step 2

Enter two moisture readings

Enter the measured starting moisture and the final moisture you plan to reach. Both are wet-basis percentages: water divided by total grain weight. The final reading must be no higher than the starting one for this drying calculation.

Step 3

Add handling only when it is separate

Leave Optional separate handling loss at zero for water-only shrink. If you have a flat handling allowance, enter its percentage of the starting weight. Select Calculate dried weight, then read the large saleable estimate and its water/handling breakdown.

Walk through one wet corn load

Let's say 1,000 lb of corn comes off the scale at 25% moisture. That means 250 lb is water and 750 lb is dry matter. If the grain is dried to 15.5% moisture, dry matter will make up 84.5% of its new weight. Divide 750 lb by 0.845 and the grain weighs 887.57 lb at the new moisture. Water removed is 1,000 − 887.57 = 112.43 lb.

Before drying1,000 lbAt 25% moisture
After water leaves887.57 lbAt 15.5% moisture
With 0.5% handling882.57 lb5 lb more deducted

If a separate handling allowance is 0.5% of the starting load, subtract 5 lb from 887.57 lb. The estimated saleable weight is 882.57 lb. Total shrink is 117.43 lb, or 11.74% of the original 1,000 lb. Those are weight percentages, not moisture points.

Why the moisture drop is not the weight drop

The moisture reading fell by 9.5 percentage points, from 25% to 15.5%. It would be tempting to take 9.5% off the starting 1,000 lb, but that gives 905 lb—too high. As water leaves, the 750 lb of dry matter stays while the total load becomes lighter. Dry matter therefore becomes a bigger fraction of the remaining weight.

Dry matter = starting weight × (100 − starting moisture)%

Weight at final moisture = dry matter ÷ (100 − final moisture)%

Water removed = starting weight − weight at final moisture

Handling loss = starting weight × separate handling %

Estimated saleable weight = weight at final moisture − handling loss

The calculation keeps full precision until display. The cards round weights for reading. Total shrink is water removed plus the separate handling loss, divided by starting weight to show a percentage of the original load.

Try the same idea with a metric load

Suppose the scale shows 10,000 kg at 20% moisture and you plan to reach 14%, with no handling deduction. Dry matter is 8,000 kg. At 14% moisture it represents 86% of the load, so the weight is 8,000 ÷ 0.86 = 9,302.33 kg. About 697.67 kg of water leaves. That is 6.98% of the starting weight, even though moisture fell by 6 points.

If you change to tonnes, the physical load is the same: about 9.3023 t at final moisture. Changing the unit does not change shrink percentage. It only changes how the mass is written.

What the optional handling allowance does

Water loss follows from the two moisture readings. Handling loss is different: grain can be lost as dust, broken kernels, spillage or other material during moving and drying. You may have a separate allowance in a plan or quote. This page applies the percentage you enter to the original measured load, then subtracts that weight after the water-only result.

Check the percentage basis before entering it

A buyer may quote a combined shrink factor per moisture point. That is not the same as a flat handling percentage of starting weight. If the quote already includes water and handling, do not enter the whole factor here as an extra loss.

For a 50 t load at 18% moisture dried to 14%, dry-matter balance gives 47.6744 t before handling. A separate 1% of starting weight is 0.5 t, leaving 47.1744 t. The total weight loss is 2.8256 t. Use this sort of check when you know the allowance is genuinely separate.

Why a buyer's ticket might show another weight

Return to the 1,000 lb corn load. Imagine a buyer quotes a combined shrink factor of 1.3% for each moisture point removed. The grain drops 9.5 points, so the buyer deducts 9.5 × 1.3% = 12.35% of the starting weight. The ticket would show 876.50 lb. That factor already includes the water allowance and an extra deduction.

This calculator882.57 lbWater balance + separate 0.5% handling
Example buyer factor876.50 lbCombined 1.3% per moisture point

The 6.07 lb difference comes from the two allowance methods, not a change in the measured grain. Do not type 1.3% into the handling field to imitate that quote: this field is a flat percent of starting weight, while the quoted factor is multiplied by moisture points and already includes water shrink. Ask which method the buyer uses before comparing figures.

Before you treat the number as a sale

The big result is a useful planning weight, not the final amount on every buyer's ticket. A buyer may use a posted shrink schedule, remove foreign material, apply grade discounts, or charge for drying. A storage plan has its own costs and risks. Those decisions need the actual buyer terms and grain condition.

  • Check the moisture sample. A poor sample changes the result even when the formula is right.
  • Check the final target. It comes from the crop and storage or sale plan, not from this calculator.
  • Keep handling separate. Do not add a combined shrink factor twice.
  • Use a matching price unit later. A price per bushel cannot be multiplied by kilograms without a crop-specific conversion.

Frequently asked questions

What does grain moisture percentage mean here?
It is wet-basis moisture: water as a percentage of the grain load’s total measured weight. Enter both starting and final moisture on this same basis.
Why is weight shrink greater than the drop in moisture points?
After drying, the same dry matter makes up a larger share of a lighter load. Dropping from 25% to 15.5% moisture is 9.5 moisture points, but the water-only weight loss is about 11.24% of the original weight.
Is dry matter the weight I can sell?
No. Dry matter excludes all water. Grain at your selected final moisture still contains water, so its weight is greater than the dry-matter weight. The saleable estimate also subtracts any handling allowance you enter.
What does the optional handling loss percentage apply to?
It is a flat percentage of the original grain weight, applied after the water-only weight is calculated. Enter zero unless you have a separate handling allowance to model.
Can I enter the buyer’s shrink factor as handling loss?
Usually no. A quoted shrink factor per moisture point may already include both water and handling. Adding it as a flat handling percentage here would double count or use the wrong basis. Ask the buyer how the quote is calculated.
Does this calculate my elevator settlement weight?
It estimates physical weight after drying plus the separate handling percentage you choose. A buyer may use a different pencil-shrink schedule, foreign-material deduction, grade discount or fee. Compare the weigh ticket and contract before treating this as a settlement amount.
Can I use bushels instead of pounds?
This page uses mass units: kilograms, metric tonnes, pounds and US short tons. Bushels are crop-specific marketing units with different standard weights, so converting to them would need the crop and its standard bushel weight.
What if starting and final moisture are equal?
Water shrink is zero. If you leave handling loss at zero, saleable weight equals starting weight. You can still enter a separate handling allowance if that is part of your plan.
Does the calculator choose a safe storage moisture?
No. Enter the final moisture required by your crop, storage plan or buyer. Safe targets vary with crop and storage conditions; this page only calculates the weight change.

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