Practical guide

Wet-Basis vs Dry-Basis Grain Moisture

Understand the denominator behind wet-basis and dry-basis moisture before adjusting grain weight or shrink.

Moisture percentage is incomplete unless its basis is named. Grain commerce commonly reports moisture on a wet basis, where water mass is divided by total wet sample mass. Some engineering and feed contexts use dry basis, where the same water mass is divided by dry matter.

For a 100 kg sample at 25% wet-basis moisture, water is 25 kg and dry matter is 75 kg. Dry-basis moisture is therefore 25 / 75 × 100 = 33.33%.

Conversion formulas

dry-basis % = 100 × wet-basis % / (100 − wet-basis %)

wet-basis % = 100 × dry-basis % / (100 + dry-basis %)

A reliable mass-balance workflow

1. Record the reported basis and measurement method.
2. Convert moisture to a fraction only after confirming the basis.
3. Calculate dry matter from the starting mass.
4. Hold dry matter constant only for a pure water-adjustment scenario.
5. List handling, respiration, dockage and processing losses separately.

Measurement boundary

An arithmetic conversion does not measure moisture. Official inspection uses representative samples, approved instruments, calibration and prescribed procedures. Do not infer official grade or safe storage from a calculated scenario.

Keep wet-basis adjustment and shrink/settlement accounting as separate worksheets. Both specialist calculators remain out of the search index until their required agriculture review is recorded.