Free sawmill tool
Timber Shrinkage Calculator
Size your green sawing dimensions to hit a target dry size, and predict moisture-driven movement — using European/Scandinavian species coefficients and the EN 1313 reference.
Target dry size → required green size
Enter the finished dry dimensions you need. We add the shrinkage allowance so the piece lands on size after drying.
mm
mm
EN 1313 reference size is at 20% MC.
%
8%12%16%18%20%
≥30% = fully green (fibre saturation).
%
Added to each dimension (total, e.g. both faces).
mm
Extra margin for variability.
%
Flat-sawn (tangential) moves most — the safe default for sawing allowance.
Advanced: fibre saturation point
Below this MC, wood shrinks; above it, no dimensional change. Typical 28–30%.
%
Required green sawn size
Thickness
—
mm
Width
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mm
both carry a way back
✓Ready — this is what you'll send.
Species shrinkage coefficients (reference)＋
| Species | Radial % | Tangential % | Volumetric % |
|---|
Total shrinkage from fibre saturation (~30% MC) to oven-dry, as a percentage of the green dimension. Source: Swedish Wood (Svenskt Trä), "Moisture-related wood movement", Table 11. Larch is given as a range; a mid value is used. Below fibre saturation, movement is treated as linear with moisture content.
Related European standards
This tool follows the EN 1313 / EN 336 convention.
After the calculation
This drying batch becomes a pack you can actually track.
A calculator answers one question once. Inventory keeps the answer — the same batch, the same target moisture, tracked while it dries.
1
Batch intake from your phoneGreen size and target moisture carry over automatically — the app tracks the batch while it dries. Free forever, no card.
2
Every pack trackedA QR label on a standard printer; scanned with the phone camera as it moves green → kiln → dry.
3
One stock viewSpecies, size, grade, drying status — one set of numbers instead of five spreadsheets.
4
EUDR chain-of-custodySupplier DDS stored, linked to the lot and carried through intake, cutting and dispatch.
Track this drying batch →
See how Inventory works
€99 / month · free forever with 5 packs · EU-hosted, Frankfurt
Continue measuring
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