American Sycamore wood movement, board-foot & weight calculator
- Janka
- 770lbf
- Density
- 34.2lb/ft³
- T/R ratio
- 1.7
- Spec. gravity
- 0.49
American Sycamore is a North American hardwood. It has a Janka side hardness of 770 lbf, a specific gravity of 0.49, and an air-dry density near 34 lb/ft³ (548 kg/m³) (mechanical values at 12% moisture content). It shrinks 8.4% tangentially and 5% radially from green to oven-dry (T/R ratio 1.7), so a 12-inch flatsawn board moves about 0.2 in (≈ 3/16 in) across a 6-point moisture swing (about 6%→12% MC).
Compute American Sycamore: movement, weight & board footage
Every number below is worked from American Sycamore's own shrinkage and density figures, not looked up from a table — change the width, moisture swing, or board size in the calculators linked alongside.
Cross-grain movement by board width
| Board width | Flatsawn (tangential) | Quartersawn (radial) |
|---|---|---|
| 2″ | 0.034″ (≈ 1/32 in) | 0.02″ (≈ 1/32 in) |
| 3″ | 0.05″ (≈ 1/16 in) | 0.03″ (≈ 1/32 in) |
| 4″ | 0.067″ (≈ 1/16 in) | 0.04″ (≈ 1/32 in) |
| 6″ | 0.101″ (≈ 3/32 in) | 0.06″ (≈ 1/16 in) |
| 8″ | 0.134″ (≈ 1/8 in) | 0.08″ (≈ 3/32 in) |
| 10″ | 0.168″ (≈ 5/32 in) | 0.1″ (≈ 3/32 in) |
| 12″ | 0.202″ (≈ 3/16 in) | 0.12″ (≈ 1/8 in) |
| 16″ | 0.269″ (≈ 9/32 in) | 0.16″ (≈ 5/32 in) |
Need a different width or moisture swing? Run the movement calculator preloaded with American Sycamore. At a T/R ratio of 1.68, American Sycamore is stable — it moves moderately more across the face than through the thickness — normal behaviour for a furniture hardwood, and predictable if boards are acclimatised before milling.
Board footage & weight, standard sizes
| Nominal size × length | Board feet | Weight |
|---|---|---|
| 1×4 × 8′ | 2.67 bd ft | 7.6 lb |
| 1×6 × 8′ | 4 bd ft | 11.4 lb |
| 1×8 × 8′ | 5.33 bd ft | 15.2 lb |
| 1×10 × 8′ | 6.67 bd ft | 19 lb |
| 1×12 × 8′ | 8 bd ft | 22.8 lb |
| 2×4 × 8′ | 5.33 bd ft | 15.2 lb |
| 2×6 × 8′ | 8 bd ft | 22.8 lb |
| 2×8 × 8′ | 10.67 bd ft | 30.4 lb |
Different length or size? Run the board foot calculator or the weight calculator, both preloaded with American Sycamore.
Seasonal movement by city
| City | Driest month (EMC) | Most-humid month (EMC) | EMC swing | 12″ board movement |
|---|---|---|---|---|
| Phoenix, AZ | Jun · 4.4% | Dec · 9% | 4.6 pts | 0.155″ (≈ 5/32 in) |
| Chicago, IL | May · 12.3% | Dec · 15.1% | 2.8 pts | 0.094″ (≈ 3/32 in) |
| Miami, FL | Apr · 12.2% | Sep · 14.4% | 2.2 pts | 0.074″ (≈ 1/16 in) |
| Boston, MA | Apr · 11.5% | Sep · 12.8% | 1.3 pts | 0.044″ (≈ 1/32 in) |
| Denver, CO | Jul · 8% | Dec · 10.5% | 2.5 pts | 0.084″ (≈ 3/32 in) |
| Seattle, WA | Jul · 12% | Dec · 16.9% | 4.9 pts | 0.165″ (≈ 5/32 in) |
Driven by American Sycamore's tangential shrinkage of 8.4%. These are outdoor equilibrium-moisture figures, so they are an upper bound — a climate-controlled interior swings less. How this is calculated.
How American Sycamore compares
Ranked against the 196 species in the Wood Handbook tables this site carries.
- Hardness: at 770 lbf, American Sycamore is harder than 38% of the 157 species with a Janka figure.
- Weight: at 34.2 lb/ft³ it is heavier than 40% of the 170 species measured — an 8-foot 1×6 board weighs about 11.4 lb.
- Stability: its T/R ratio of 1.68 is more even than 65% of the 196 species here — as humidity changes, 35% of them hold their shape more evenly.
See American Sycamore plotted against every species we carry: the full Janka hardness chart and the full density chart .
Species with a similar working profile
Closest matches on hardness, weight and stability together — useful when American Sycamore is unavailable or priced out.
- Coast Douglas-fir is a common substitute for American Sycamore : nearly identical hardness, about the same weight, and similarly stable in service.
- Black Ash is a common substitute for American Sycamore : 10% harder, about the same weight, and similarly stable in service.
- Eastern Redcedar is a common substitute for American Sycamore : 16% softer, about the same weight, and similarly stable in service.
- African Mahogany is a common substitute for American Sycamore : nearly identical hardness, 14% lighter, and similarly stable in service.
| Species | Janka | Density | T/R |
|---|---|---|---|
| Coast Douglas-fir | 710 lbf | 33.5 | 1.58 |
| Black Ash | 850 lbf | 34.2 | 1.56 |
| Eastern Redcedar | 650 lbf | 32.8 | 1.52 |
| African Mahogany | 830 lbf | 29.4 | 1.8 |
About American Sycamore
American sycamore (Platanus occidentalis) is sometimes called buttonwood or buttonball tree. Sycamore grows from Maine to Nebraska, southward to Texas, and eastward to Florida. The heartwood of sycamore is reddish brown; the sapwood is light in color and from 4 to 8 cm (2 to 3 in.) wide. The wood has a fine texture and interlocked grain. It has high shrinkage in drying. It is moderately heavy, moderately hard, moderately stiff, moderately strong, and it has good shock resistance. Sycamore is used principally for lumber, veneer, railroad crossties, slack cooperage, fence posts, and fuel. The lumber is used for furniture, boxes (particularly small food containers), pallets, flooring, handles, and butcher blocks. Veneer is used for fruit and vegetable baskets and some decorative panels and door skins.
Durability & sustainability
Decay resistance: the Wood Handbook rates American Sycamore heartwood slightly or nonresistant to fungal decay (Table 14-1 rates the Sycamore genus as a whole, without splitting by growth region or variety) . Ratings are for heartwood only and the table's own note cautions that resistance varies substantially within a species; treat this as a general indicator, not a guarantee, especially for ground contact. Wood Handbook, Chapter 14: Biodeterioration of Wood (Arango, Lebow, Glaeser), USDA Forest Products Laboratory, FPL-GTR-282 (2021), Table 14-1. Public domain.
CITES status: not listed on any CITES Appendix — no international-trade restriction applies to American Sycamore.
Properties
| Specific gravity | 0.49 |
|---|---|
| Janka hardness (side) | 770 lbf |
| Density (air-dry, 12% MC) | 34.2 lb/ft³ (548 kg/m³) ovendry-weight basis: 30.6 lb/ft³ |
| Weight per board foot (air-dry) | 2.85 lb |
| Radial shrinkage (green→oven-dry) | 5% |
| Tangential shrinkage (green→oven-dry) | 8.4% |
| Volumetric shrinkage (green→oven-dry) | 14.1% |
| T/R ratio (stability indicator) | 1.7 |
Shrinkage is total green-to-oven-dry (Table 4-3); strength values are at 12% MC. Full bases and the derivation formulas are on the methodology page.
Data: USDA Forest Products Laboratory, Wood Handbook FPL-GTR-282 (2021), public domain.