LumberLogic
Board Movement Calculator — Estimate dimensional change from moisture.
Inputs
The Workshop Result
Estimated movement
0.504 in
≈ 1/2" (nearest 1/16")
Visualizer
Bar scale represents relative movement
Note
White Oak has a high movement ratio. Before building, check the grain structure visually.
Why does wood move?
Wood is hygroscopic—it absorbs and releases moisture from the air. As humidity rises, wood expands; as it falls, wood shrinks. This dimensional change follows predictable patterns based on species and how the board was cut from the log.
The wood expansion formula used in this calculator multiplies board width by a species-specific coefficient and the expected moisture change (%). Tangential movement (flat sawn) is typically 2–3× greater than radial movement (quarter sawn), which is why furniture joinery rules often recommend orienting panels to allow for cross-grain expansion. Frames, breadboard ends, and floating panels are designed to accommodate this movement and prevent cracking or joint failure.
Understanding these coefficients helps architects, 3D artists, and woodworkers design pieces that remain stable across seasons and climates.