Free farm tool
Grain Drying Calculator
Enter wet tonnes and moisture levels - see the saleable tonnage after drying, the weight lost as water, and the estimated cost.
Dried weight
95.91 t
Weight lost as water
4.09 t (4.1%)
Estimated drying cost
£875
100 t at 18% dried to 14.5% leaves 95.91 t of saleable grain - plus roughly £875 in drying charges (3.5 points at £2.5 per tonne per point).
How the sums work
Drying doesn't change the amount of grain - it removes water, and the water was part of the weight. Dry matter is conserved, so:
dried weight = wet weight × (100 − current moisture%) ÷ (100 − target moisture%)
Worked example: 100 tonnes of wheat at 18% dried to 14.5% gives 100 × 82 ÷ 85.5 = 95.9 tonnes. The missing 4.1 tonnes left as water vapour. That weight loss is real money at selling time, which is why it belongs in the drying decision alongside the fuel.
The full cost of drying
- Weight loss: the tonnes of water removed, as above. Usually the biggest single cost in the decision.
- Fuel and running cost: commonly quoted as £/tonne per percentage point removed; £2–£3.50 covers most UK setups in a normal year.
- Time and handling: drier throughput can bottleneck harvest, and every extra handling knocks a little quality off.
Against that sits the buyer's alternative: moisture claims for taking it wet, or rejection above the contract maximum. Our grain moisture content guide has the target figures by crop - including the difference between “passes the contract” and “safe to store until spring”.
Record moisture per load, not per shed
This calculator is only as good as its inputs, and the input that drifts is moisture. Loads cut at 8am in dew and 3pm in sun off the same field can differ by two points. Sampling and recording moisture against each weighed load - the same habit as a complete weighbridge ticket - is what lets you dry the wet loads instead of the whole heap, and explain the shed total in spring.
Frequently asked questions
How much weight does grain lose when dried?
The water removed is the weight lost. Drying wheat from 18% to 14.5% moisture loses about 4.1% of the wet weight - so 100 wet tonnes becomes roughly 95.9 saleable tonnes. The formula: dried weight = wet weight × (100 − current moisture) ÷ (100 − target moisture).
What does grain drying cost per tonne in the UK?
A common way to quote it is per tonne per percentage point removed - typically £2–£3.50 depending on fuel and the drier. Commercial and co-op stores often charge a flat rate instead, commonly £10–£25 per tonne for a normal harvest-moisture load. Your own drier's true cost depends mostly on fuel price and throughput.
Is it worth drying grain or selling it wet?
Compare the buyer's moisture claim (the price deduction for wet grain) against your drying cost plus the weight loss. In a wet year, buyers' claims tend to rise and drier queues lengthen, which usually swings the sums towards drying on farm if you have the capacity. Run both numbers before deciding - that's what this calculator is for.
Why is my dried tonnage less than the weighbridge weight at harvest?
Because harvest weights include water that the drier then removes. If the shed total looks short in the spring against what the fields weighed in the summer, moisture loss is usually most of the answer - and per-load moisture records are how you prove it rather than suspect it.
Weighing loads this harvest? Stop adding them up by hand.
Harvestt records every weighbridge load against crop, field, and shed - and does this arithmetic for you, live.
Try Harvestt