Moisture Content Calculator — Wet & Dry Basis
Enter the wet (fresh) mass and the mass after oven-drying to constant weight to get the moisture content on both a wet basis and a dry basis, the absolute water mass, and the dry-matter fraction.
g
g
Water mass as a percentage of the wet (total) mass — the most common field and food-science convention
25 %
moisture (wb)Water
25%
Dry matter
75%
- 1
Water mass = wet mass − dry mass
100 − 75 = 25 - 2
Moisture content (wet basis)
25 ÷ 100 × 100 = 25Water expressed as a percentage of the total (wet) mass.
How does this calculator work?
Moisture content (wet basis) = (wet mass − dry mass) / wet mass × 100 %; dry basis = (wet − dry) / dry × 100 %. Weigh the sample fresh and again after oven-drying to constant weight at 105 °C. Wet-basis is the everyday convention; dry-basis is preferred in wood and industrial drying because the dry-mass denominator stays constant.
Formula
How this is calculated
Moisture content quantifies how much water a sample contains relative to its total or its dry weight. The oven-dry method — the reference technique in soil science, food science and agriculture — involves weighing a sample, drying it in a oven at 105 °C (soil) or 70–105 °C (food/biomass) until the weight stops changing, then weighing it again. The water mass is the difference mw − md.
The wet-basis moisture content MC_wb = (mw − md)/mw × 100 expresses water as a fraction of the total wet weight. This is the everyday convention for food labelling, farming produce specifications, and most quick field measurements. The dry-basis moisture content MC_db = (mw − md)/md × 100 expresses water as a fraction of the bone-dry solids weight. Dry-basis values can exceed 100 % (e.g. freshly cut wood) because you are comparing water mass to a smaller denominator; they are preferred in wood science, paper manufacture, and drying-process engineering because the dry-mass denominator is constant throughout the drying process.
Conversion between the two: MC_db = MC_wb / (1 − MC_wb/100) and MC_wb = MC_db / (1 + MC_db/100). The calculator assumes the measured dry mass represents fully dry material; residual bound water in very hygroscopic materials (zeolites, silica gel) may cause a slight overestimate of the true water content.
Frequently asked questions
Wet-basis uses total wet mass as the denominator; dry-basis uses the dry mass. They give different percentages for the same sample. Food and agriculture conventionally use wet-basis; wood drying and paper industries use dry-basis. For high-moisture materials, MC_db can exceed 100 %.
Any consistent unit (g, kg, lb) — the percentages are the same because moisture content is a ratio. The calculated water mass will be in whichever unit you entered.
It should not — after drying, mass can only decrease or stay the same. A dry mass greater than the wet mass indicates a measurement or data-entry error, so the calculator shows a warning and returns no result.
Also known as
TG we-Calculate Editorial Team. (2026). Moisture Content Calculator — Wet & Dry Basis [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/moisture-content-calculator
TG we-Calculate Editorial Team. "Moisture Content Calculator — Wet & Dry Basis." TG we-Calculate. 2026. https://we-calculate.com/calculator/moisture-content-calculator.
TG we-Calculate Editorial Team, "Moisture Content Calculator — Wet & Dry Basis," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/moisture-content-calculator
@misc{wecalculate_moisture_content_calculator, title = {Moisture Content Calculator — Wet & Dry Basis}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/moisture-content-calculator}}, year = {2026}, note = {TG we-Calculate} }
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