Wood expands and contracts with changes in moisture content. The amount varies by species,
how the board was cut from the log, and how much your climate swings between seasons.
Enter your details below to see what to expect — and how to plan for it.
Methodology: Movement is calculated as Width × (shrinkage% ÷ 28) × ΔMC,
where 28% is the approximate fiber saturation point and ΔMC is the expected change in equilibrium
moisture content (EMC) for your climate. EMC values are derived from the Wood Handbook
(USDA Forest Service) formula at 70°F / 21°C. Shrinkage coefficients are sourced from
The Wood Database
and the USDA Wood Handbook. All values are estimates — actual movement will vary with
individual board characteristics, moisture history, and finishing choices.