Grain shrink calculator
Enter the amount of wet grain in any unit (bushels, pounds, tonnes), its moisture and the moisture you dry it to, plus a handling loss if you count one. The calculator returns the weight left after drying and the shrink, in the same unit you entered.
Runs in your browser: nothing you enter is sent anywhere.
How to use
- Enter the amount of wet grain.
- Enter the moisture before and after drying.
- Add a handling loss if your dryer or elevator counts one, then read the results.
How it works
- dry weight = wet weight × (100 − moisture before) ÷ (100 − moisture after);
- water shrink = (moisture before − moisture after) ÷ (100 − moisture after);
- grain after drying = dry weight × (1 − handling loss);
- total shrink = 1 − grain after drying ÷ wet weight; shrink per point = total shrink ÷ points removed.
Example
100 bushels of corn at 25 % dried to 15.5 %, with a 0.5 % handling loss:
- 100 × 75 ÷ 84.5 = 88.76; water removed 11.24 (11.24 %);
- 88.76 × 0.995 = 88.31 left after drying;
- total shrink 11.69 %, which is 11.69 ÷ 9.5 = 1.23 % per point.
30 t of wheat at 18 % dried to 14 % with no handling loss comes to 28.6 t, a 4.65 % shrink.
Tips and common mistakes
- The moisture after drying is usually the market standard: 15.5 % for corn in the US, 13–14 % for wheat.
- Overdrying below the standard costs you weight you are not paid for.
- An elevator’s shrink table may round, add handling and charge for drying separately; compare like with like.
Frequently asked questions
How do you calculate grain shrink?
The dry matter stays the same while water leaves: dry weight = wet weight × (100 − initial moisture) ÷ (100 − final moisture). The water shrink in per cent is (initial − final) ÷ (100 − final) × 100.
Why is shrink more than 1 % per point?
Each point of moisture is a per cent of the final weight, not of the wet weight. Drying corn to 15.5 % removes 1.18 % of the weight per point, before any handling loss.
What is handling loss?
Fine material, dust and broken kernels lost in drying, cleaning and moving grain. Elevators often add about 0.5–1 % to the water shrink in their shrink factor; use their figure to check a settlement.
What unit should I use?
Any. Shrink is a ratio, so the result comes out in the unit you entered: bushels, pounds, kilograms or tonnes.