Calculate wet-basis moisture content, dry matter, and water mass from wet and oven-dry sample weights.
Moisture content from wet and dry weights
Enter weights measured in the same unit. The result uses moisture content = (wet weight - dry weight) / wet weight × 100.
About moisture content
Moisture content describes how much water is present in a material compared with the material's measured wet mass. It is important in agriculture, soil testing, timber processing, construction, food production, pharmaceuticals, and laboratory quality control. Water changes weight, strength, storage stability, electrical behavior, and susceptibility to biological growth, so a repeatable moisture measurement helps people compare samples and decide whether a product is ready to store, process, or use.
This calculator uses the common wet-basis definition. First weigh the sample before drying to obtain wet weight. Dry it by the method required for the material, allow it to cool in a controlled environment, and weigh it again to obtain dry weight. The mass lost during drying is treated as water mass. Dividing that loss by the original wet weight and multiplying by 100 gives moisture content as a percentage. Dry matter is the complementary percentage, calculated as dry weight divided by wet weight times 100. Together, moisture content and dry matter add to 100 percent.
Accurate inputs depend on good sampling. A handful taken from the surface may not represent a large grain bin, soil profile, board, or food batch. Mix or collect several representative subsamples when the testing standard permits it. Use a calibrated balance, avoid spilling solids between measurements, and prevent a dried sample from absorbing humidity while it cools. The wet and dry entries may technically use any identical mass unit because the units cancel in the percentage, although this interface labels grams for clarity and reports the water-mass difference in grams.
Wet-basis moisture should not be confused with dry-basis moisture. Dry-basis calculations divide water mass by dry solid mass and can exceed 100 percent, while wet-basis values normally range from zero to 100 percent. Engineering specifications and commodity standards may choose either convention, so always confirm which basis a target value uses. This tool reports wet basis because it is intuitive for product composition and is widely used in food and agricultural work.
Drying temperature and duration also matter. Excessive heat can drive off volatile compounds other than water and make moisture appear too high, while incomplete drying leaves water behind and makes it appear too low. Follow the relevant oven, microwave, moisture-meter, or loss-on-drying standard for the material. The calculator performs the arithmetic consistently, but the reliability of the answer ultimately reflects the quality of the measurements entered.
Moisture content examples
Measured weights
Moisture result
Interpretation
150 g wet, 120 g dry
20%
The sample lost 30 g of water and contains 80% dry matter.
250 g wet, 175 g dry
30%
The 75 g mass loss is 30% of the original sample.
80 g wet, 76 g dry
5%
A small 4 g loss indicates a relatively dry material.
How to calculate moisture content
Weigh the representative sample before drying and enter its wet weight.
Dry the sample according to the appropriate material-testing standard.
Weigh the cooled sample and enter its dry weight in the same unit.
Select Calculate Moisture Content to see moisture, dry matter, and water mass.
Moisture content FAQ
What formula does this moisture calculator use?
It uses wet-basis moisture content: wet weight minus dry weight, divided by wet weight, then multiplied by 100. It also reports dry matter and the measured water-mass loss.
Can I enter ounces or kilograms instead of grams?
Yes, the percentage is unchanged when both weights use the same unit. The displayed water-mass label remains grams, so convert that difference if you use another unit.
Why can dry-basis moisture exceed 100 percent?
Dry-basis moisture compares water with only the dry solids, so water can outweigh those solids. This calculator instead uses the original wet sample as the denominator.
What if the dry weight is greater than the wet weight?
That usually indicates a measurement, transcription, or sample-handling problem. The calculator rejects that combination because ordinary drying should not add mass.
Does drying remove only water?
Not always, because volatile oils or solvents may also evaporate at high temperatures. Use the prescribed method for your material so the measured mass loss represents moisture as closely as possible.