Enter a sample's wet (as-is) weight and dry weight to get moisture content on both a wet basis and a dry basis, plus the water mass removed and dry matter content.
Results
Calculated
Moisture content (wet basis)
—
Water mass ÷ wet weight × 100
Moisture content (dry basis)
—
Water mass ÷ dry weight × 100
Water mass removed
—
Wet weight − dry weight
Dry matter content
—
Dry weight ÷ wet weight × 100
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How to use this calculator
Enter the wet weight — the sample's weight as collected, before any drying — and the dry weight, the same sample's weight after it has been dried to a constant (no longer changing) weight. Click Calculate to get moisture content on both a wet basis and a dry basis, plus the water mass removed and the dry matter content. Click Clear to reset the fields to their defaults.
The formulas
Moisture content compares the water lost during drying to either the original wet weight or the remaining dry weight:
Wet basis is the standard used for grain, food, and most commercial moisture specs, since it reports water as a share of what you actually weighed. Dry basis is common in wood science, soil science, and composting, since it keeps the dry-matter reference fixed as moisture changes. The two are related by MCdb = MCwb ÷ (1 − MCwb/100) × 100.
Interpreting the results
The two highlighted cards show the same water loss expressed on each basis — dry-basis will always read higher than wet-basis for the same sample, and can exceed 100% when a sample holds more water than dry matter (common in fresh produce or green wood). The water mass removed is simply wet weight minus dry weight in your chosen unit; dry matter content is the complement of the wet-basis figure (100% − MCwb).
Frequently Asked Questions
What is the difference between wet basis and dry basis moisture content?
Wet basis (MCwb) expresses the water mass as a percentage of the total wet (as-is) sample weight: (wet - dry) / wet x 100. Dry basis (MCdb) expresses the same water mass as a percentage of the dry sample weight instead: (wet - dry) / dry x 100. Wet basis is standard in grain trading and food science; dry basis is common in wood science, soil science, and composting because it keeps the dry-matter reference fixed even as water content changes.
How do I measure wet and dry weight for this calculator?
Weigh the sample as collected for the wet weight, then dry it (commonly in an oven at a standard temperature for the material, such as 103 degrees C for grain) until the weight stops changing, and weigh it again for the dry weight. Use the same scale and units for both measurements so the difference reflects only water loss.
Can moisture content be over 100 percent?
Wet-basis moisture content cannot exceed 100% because the water mass can never exceed the total wet mass. Dry-basis moisture content can exceed 100% when a sample holds more water than dry matter, which is common for fresh produce, wet soil, and green wood.
Why is dry weight required instead of just guessing moisture content?
Moisture content is defined by the actual mass of water lost during drying, not by appearance or texture. The oven-dry (or reference-dry) weight is the only way to isolate that water mass precisely, which is why standard test methods always compare a wet weight to a measured dry weight rather than estimating.