Wood Shrinkage Calculator

Predict how wood dimensions will change as moisture content decreases. Accounts for species-specific shrinkage rates and cut orientation.

Units:
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Results

Thickness

1.000"
Original
0.968"
Final
Shrinks 0.0321" (3.21%)
Using 4.5% radial shrinkage

Width

12.000"
Original
11.314"
Final
Shrinks 0.6857" (5.71%)
Using 8% tangential shrinkage
Shrinkage values: Radial 4.5%, Tangential 8%(T/R Ratio: 1.78)

How It Works

Shrinkage Formula: ΔD = D × (S/100) × (MC_start - MC_target) / FSP

Wood shrinks differently along different grain directions. Tangential shrinkage (parallel to growth rings) is typically 1.5-2× greater than radial shrinkage (perpendicular to rings).

Shrinkage only occurs below the Fiber Saturation Point (FSP), typically around 28% MC. Above FSP, water exists as "free water" in cell cavities and doesn't affect dimensions.

Wood Shrinkage Calculator - Predict Dimension Changes | ForestSource | ForestSource