How Much Will a 12 Inch Hard Maple Panel Move
+0.2376" (+6 mm)
- Species: Hard Maple (tangential shrinkage 9.9%)
- Starting width: 12"
- Moisture content: 6% -> 12% (a typical dry-to-humid seasonal swing)
MethodΔD = D x ΔMC x (shrinkage% / 30 / 100)
Your actual humidity swing may be smaller or larger than the 6-12% MC example used here — run your own numbers in the movement calculator.
A 12" wide hard maple panel will grow about +0.2376" (+6 mm) across its width moving from 6% to 12% moisture content — the second-highest movement figure of any species this site tracks, behind only white oak.
Why this one specifically
That's a surprising number given how often hard maple ends up on butcher blocks and bowling-alley floors — surfaces that get wet regularly and still need to stay flat. The trick is orientation: those applications almost never use flat-sawn maple face-up the way this figure assumes. Butcher blocks are typically built end-grain-up or edge-grain, presenting the more stable radial face to the surface rather than the tangential face this 12-inch flat panel figure describes, which is a large part of why a maple cutting board that sees regular water contact doesn't visibly warp the way a flat-sawn maple panel of the same width would.
What moves the number
Grain orientation is the single biggest lever for hard maple specifically, given how far apart its radial and tangential figures sit — a radial-facing (quartersawn or edge-grain) maple board moves meaningfully less than this tangential number. Width scales the result directly beyond that.