How this calculator works
Drying loss is treated as water mass. Divide that loss by dry solids mass for dry-basis moisture, commonly used for soil and wood, or by original wet mass for wet-basis moisture, often used for agricultural products. Container masses must be subtracted first. Volatile compounds lost during drying, incomplete drying and decomposition can bias the result. The required drying temperature and end-point depend on the material and test method.
Formula
mw = mwet - mdry. Dry basis wd = mw/mdry. Wet basis ww = mw/mwet. ww = wd/(1 + wd); wd = ww/(1 - ww).
Worked example
A 1.2 kg wet sample that dries to 1 kg contains 0.2 kg water: 20% dry basis and 16.66666667% wet basis. A 2 kg sample that dries to 1 kg has 100% dry-basis moisture.
Advertisement
Frequently asked questions
Can moisture content exceed 100%?
Dry-basis moisture can, because water mass can exceed dry solids mass. Wet-basis moisture stays below 100% when solids remain.
Should the container be included?
No. Subtract its tare mass from both measurements before entering sample masses.
Is every drying loss water?
Not necessarily. The calculation assumes it is; a suitable material-specific drying method is needed to justify that assumption.