Wood Moisture Content Calculator from Wet & Dry Weight

Mass measurements

The dry-basis moisture-content formula

Wood moisture content is calculated from the amount of water in the sample relative to the oven-dry wood mass.

Worked example

A sample with a wet mass of 1,250 g and an oven-dry mass of 1,000 g contains 250 g of water. Its dry-basis moisture content is 250 ÷ 1,000 × 100 = 25%.

Why dry basis can exceed 100%

Because the denominator is the oven-dry mass, a sample can theoretically contain water weighing more than the dry wood mass. A dry-basis moisture-content result above 100% is therefore not automatically a mathematical error.

Measurement quality

For laboratory work, the specimen preparation, weighing, drying procedure and endpoint matter. For field use, electronic moisture meters introduce their own calibration and measurement considerations. The calculator only performs the arithmetic from the supplied masses.

Moisture content versus equilibrium moisture content

Moisture content is a measurement of the wood specimen. Equilibrium moisture content describes the moisture level a wood product tends toward under particular environmental conditions. They are related but not interchangeable.

Frequently Asked Questions

Which mass goes in the denominator?

The oven-dry mass for the standard dry-basis calculation.

Can wet and dry masses use different units?

Not directly. Convert them to the same mass unit first.

What if wet mass equals dry mass?

The calculated dry-basis moisture content is 0%.

Can moisture content be negative?

A negative result indicates the entered measurements are inconsistent with a normal wet-versus-dry test.

Does this replace a moisture meter?

No. It calculates moisture content from measured masses and does not perform measurement itself.