Grain Moisture Shrinkage Calculator & Wet → Dry Weight
Dries down wheat
See exactly how much your grain weighs after drying — enter the weight and the moisture you're drying from and to, and get the dried weight, water removed, shrinkage % and value at weight.
Safe storage moisture for wheat is about 12%; common market moisture ~12%.
Drying 1,000 kg of wheat from 20% to 12% moisture leaves 909 kg — a shrinkage of 9.09% as 91 kg of water is driven off. The 800 kg of dry matter (the grain itself) doesn't change.
Next: dry to about 12% for safe storage — wetter grain heats, moulds and is docked at the mandi/elevator. Account for this shrinkage when comparing a wet sale now against drying and storing.
Assumes dry matter is conserved (water-only loss). Real drying has small handling losses; moisture-meter readings vary by instrument.
Grain drying — key facts
- Formula
- wet × (100−wet%) ÷ (100−target%)
- What's lost
- water only — grain unchanged
- Wheat safe storage
- ≈ 12%
- Paddy / maize
- ≈ 13–14%
- Oilseeds (mustard)
- ≈ 8%
- 20%→14% on 1 t
- ≈ 7% shrink (930 kg)
- Too wet
- heats, moulds, docked
- Privacy
- Runs in your browser; nothing uploaded
Why drying changes the weight
Grain weight is part kernel (dry matter) and part water. Drying drives off water but leaves the dry matter untouched, so as the moisture percentage falls, the total weight falls with it. The relationship is exact: dried weight = wet weight × (100 − wet moisture) ÷ (100 − target moisture). The wetter the grain at harvest, the more weight it sheds reaching a storable moisture — which is why a load weighed wet at the field is heavier than the same grain after the drier.
That shrinkage matters at the weighbridge and in your storage plan. Sell wet and you sell more weight but usually take a price dock and a spoilage risk; dry first and you lose weight but protect quality and storability and often net more. This tool puts numbers on both sides — dried weight, water removed and the value at each weight — so you can dry to a safe storage moisture and decide when to sell with the figures in front of you.
Know your dried weight
See exactly what a wet load will weigh once dried to your target moisture.
Dry for safe storage
Hit the safe-storage moisture for each grain so it won't heat, mould or attract insects.
Compare wet vs dry sale
Weigh the value of selling heavier wet grain against drying and storing it.
Plan drying
Estimate the water to remove so you size drying time, fuel and aeration.
Frequently Asked Questions
How do you calculate grain shrinkage from drying?+
Dry matter stays constant, so dried weight = wet weight × (100 − wet moisture%) ÷ (100 − target moisture%). For 1000 kg at 20% moisture dried to 14%, that's 1000 × 80 ÷ 86 ≈ 930 kg — about 7% shrinkage. This tool computes the dried weight, water removed and shrink % for you.
Why does grain lose weight when dried?+
Drying removes water, not grain. The dry matter — the actual kernels — doesn't change, but because water has weight, lowering the moisture percentage reduces the total weight. The wetter the grain, the more weight is lost to reach a given target.
What is safe storage moisture?+
It's the moisture level at which grain can be stored without heating, moulding or insect problems — roughly 12% for wheat, 13% for paddy and maize, and lower for oilseeds like mustard. The calculator shows the safe figure for each grain and defaults the target to it.
What is the difference between market and storage moisture?+
Market (or trade) moisture is the level buyers accept without a dockage, often a touch higher than safe-storage moisture. For long storage on-farm you usually dry slightly below market moisture to be safe; for immediate sale you may only need to reach the market figure.
How much weight will I lose drying from 18% to 13%?+
Roughly 5.7% — dried weight = wet × (100−18) ÷ (100−13) = wet × 82 ÷ 87. So 1000 kg becomes about 943 kg. Enter your own figures to get the exact shrinkage for your grain and moisture levels.
Should I sell wet or dry my grain first?+
It depends on the price dock for wet grain, drying cost and storage. Wet grain is heavier (more weight to sell) but is usually docked on price and risks spoilage; drying loses weight but protects quality and often fetches a better net price. Use the value figures here alongside your drying cost to compare.
Does this account for handling losses?+
No — it assumes only water is removed and dry matter is fully conserved. Real drying and handling add small mechanical losses (broken grain, dust, spillage), so actual dried weight may be a little lower than the calculated figure.
How accurate are moisture meter readings?+
Meters vary by type and calibration and can read differently on hot or freshly harvested grain. Take several readings, let samples reach a steady temperature, and calibrate against an oven test when precision matters — the calculation is only as good as the moisture figures you enter.
What moisture should I harvest at?+
Many crops are harvested a little wet to beat weather and shattering losses, then dried down for storage — for example maize is often harvested around 20–25% and dried to 13–14%. Harvesting too dry risks field losses; too wet means more drying. This tool quantifies the drying weight change.
Can I use this for any unit of weight?+
Yes — the shrinkage percentage is the same whatever the unit, and the dried weight comes out in the same unit you enter (kg, quintals, tonnes or bags). Just keep the weight and the result in one consistent unit.