Wood Expansion Calculator

Predict wood movement from humidity changes and build with the right allowances.

Wood Expansion Calculator

Estimate how much a board will expand or contract due to humidity changes for common wood species.

Formula

`ΔW = W × C × ΔMC`

How to use

Select species and humidity/MC range.
Enter panel width along tangential direction.
Design joinery to allow expected movement.

Pro tips

• Float panels; don’t trap them.
• Avoid cross-grain glue-ups.

FAQs

Does finish stop movement?

No—only slows exchange.

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