Free woodworking tool
Wood Movement Calculator
Solid wood expands and shrinks with seasonal humidity changes. Use this calculator to estimate how much a board may move across its width, so you can plan clearances, fixing methods, and joinery more confidently.
When this helps most
Useful for tabletops, shelves, cabinet parts, floating panels, frames, and other solid-wood parts where ignoring seasonal movement can lead to gaps, binding, or splitting.
Board details
Species use estimated dimensional-change coefficients for across-the-grain movement.
Enter a coefficient per 1% moisture-content change if you want to use your own reference value.
Flat-sawn boards usually move more across their width than quarter-sawn boards.
Enter the width across the grain. Most noticeable movement happens across width, not length.
How would you like to calculate?
Best when you already know the moisture-content range you want to compare.
This mode uses simple estimated moisture-content equivalents for easier customer planning.
No results yet
Enter your board details, then compare either moisture values or service conditions to estimate seasonal movement.
Estimated seasonal movement
0.000 in / 0.00 cm
What this means
This is an estimate of across-the-grain movement for project planning. Actual board behaviour can vary with grain angle, board selection, finishing, construction method, storage, and environment.
Simple rule of thumb
Wider solid-wood parts usually need more movement allowance. If a board is fixed too tightly across the grain, seasonal change can cause stress, gaps, or splitting.
This calculator estimates across-the-grain wood movement from board width, wood species, board cut, and moisture-content change.
Flat-sawn boards are calculated using tangential movement values, while quarter-sawn boards use radial movement values.
The estimate is intended for practical project planning, including clearances, fixing methods, floating panels, slots, and other movement-friendly details.
Reference: based on USDA Forest Products Laboratory guidance on dimensional change and moisture-related wood movement.