Bur Oak wood movement, board-foot & weight calculator
- Janka
- 1,370lbf
- Density
- 44.7lb/ft³
- T/R ratio
- 2
- Spec. gravity
- 0.64
Bur Oak is a North American hardwood. It has a Janka side hardness of 1,370 lbf, a specific gravity of 0.64, and an air-dry density near 45 lb/ft³ (716 kg/m³) (mechanical values at 12% moisture content). It shrinks 8.8% tangentially and 4.4% radially from green to oven-dry (T/R ratio 2), so a 12-inch flatsawn board moves about 0.21 in (≈ 7/32 in) across a 6-point moisture swing (about 6%→12% MC).
Compute Bur Oak: movement, weight & board footage
Every number below is worked from Bur Oak'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″ | 0.035″ (≈ 1/32 in) | 0.018″ (≈ 1/32 in) |
| 3″ | 0.053″ (≈ 1/16 in) | 0.026″ (≈ 1/32 in) |
| 4″ | 0.07″ (≈ 1/16 in) | 0.035″ (≈ 1/32 in) |
| 6″ | 0.106″ (≈ 3/32 in) | 0.053″ (≈ 1/16 in) |
| 8″ | 0.141″ (≈ 5/32 in) | 0.07″ (≈ 1/16 in) |
| 10″ | 0.176″ (≈ 3/16 in) | 0.088″ (≈ 3/32 in) |
| 12″ | 0.211″ (≈ 7/32 in) | 0.106″ (≈ 3/32 in) |
| 16″ | 0.282″ (≈ 9/32 in) | 0.141″ (≈ 5/32 in) |
Need a different width or moisture swing? Run the movement calculator preloaded with Bur Oak. At a T/R ratio of 2, Bur Oak is moderately unstable — it moves substantially more tangentially than radially, so flatsawn stock is noticeably cup-prone and quartersawn stock is worth the extra cost in wide panels.
Board footage & weight, standard sizes
| Nominal size × length | Board feet | Weight |
|---|---|---|
| 1×4 × 8′ | 2.67 bd ft | 9.9 lb |
| 1×6 × 8′ | 4 bd ft | 14.9 lb |
| 1×8 × 8′ | 5.33 bd ft | 19.9 lb |
| 1×10 × 8′ | 6.67 bd ft | 24.8 lb |
| 1×12 × 8′ | 8 bd ft | 29.8 lb |
| 2×4 × 8′ | 5.33 bd ft | 19.9 lb |
| 2×6 × 8′ | 8 bd ft | 29.8 lb |
| 2×8 × 8′ | 10.67 bd ft | 39.7 lb |
Different length or size? Run the board foot calculator or the weight calculator, both preloaded with Bur Oak.
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 | 0.162″ (≈ 5/32 in) |
| Chicago, IL | May · 12.3% | Dec · 15.1% | 2.8 pts | 0.099″ (≈ 3/32 in) |
| Miami, FL | Apr · 12.2% | Sep · 14.4% | 2.2 pts | 0.077″ (≈ 1/16 in) |
| Boston, MA | Apr · 11.5% | Sep · 12.8% | 1.3 pts | 0.046″ (≈ 1/32 in) |
| Denver, CO | Jul · 8% | Dec · 10.5% | 2.5 pts | 0.088″ (≈ 3/32 in) |
| Seattle, WA | Jul · 12% | Dec · 16.9% | 4.9 pts | 0.172″ (≈ 3/16 in) |
Driven by Bur Oak's tangential shrinkage of 8.8%. These are outdoor equilibrium-moisture figures, so they are an upper bound — a climate-controlled interior swings less. How this is calculated.
How Bur Oak compares
Ranked against the 196 species in the Wood Handbook tables this site carries.
- Hardness: at 1,370 lbf, Bur Oak is harder than 71% of the 157 species with a Janka figure.
- Weight: at 44.7 lb/ft³ it is heavier than 73% of the 170 species measured — an 8-foot 1×6 board weighs about 14.9 lb.
- Stability: its T/R ratio of 2 is more even than 32% of the 196 species here — as humidity changes, 68% of them hold their shape more evenly.
See Bur Oak 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 Bur Oak is unavailable or priced out.
- Sugar Maple is a common substitute for Bur Oak : nearly identical hardness, about the same weight, and similarly stable in service.
- White Oak is a common substitute for Bur Oak : nearly identical hardness, about the same weight, and similarly stable in service.
- Northern Red Oak is a common substitute for Bur Oak : nearly identical hardness, about the same weight, and similarly stable in service.
- American Beech is a common substitute for Bur Oak : nearly identical hardness, about the same weight, and similarly stable in service.
| Species | Janka | Density | T/R |
|---|---|---|---|
| Sugar Maple | 1,450 lbf | 44 | 2.06 |
| White Oak | 1,360 lbf | 47.5 | 1.88 |
| Northern Red Oak | 1,290 lbf | 44 | 2.15 |
| American Beech | 1,300 lbf | 44.7 | 2.16 |
About Bur Oak
The Wood Handbook describes Bur Oak as part of the Oak (White Oak Group); the account below is of that group, which Bur Oak belongs to.
White oak lumber comes chiefly from the South, South Atlantic, and Central States, including the southern Appalachian area. Principal species are white (Quercus alba), chestnut (Q. montana), post (Q. stellata), overcup (Q. lyrata), swamp chestnut (Q. michauxii), bur (Q. macrocarpa), chinkapin (Q. muehlenbergii), and swamp white (Q. bicolor). The sapwood of the white oaks is nearly white and roughly 2 to 5 cm (1 to 2 in.) wide. The heartwood is generally grayish brown. Heartwood pores are usually plugged with tyloses, which tend to make the wood impenetrable to liquids. Consequently, most white oaks are suitable for tight cooperage, although many heartwood pores of chestnut oak lack tyloses. The wood of white oak is somewhat heavier than the wood of red oak. Its heartwood has good decay resistance. White oaks are usually cut into lumber, railroad crossties, cooperage, mine timbers, fence posts, veneer, fuelwood, and many other products. High-quality white oak is especially sought for tight cooperage. An important use of white oak is for planking and bent parts of ships and boats; heartwood is often specified because of its decay resistance. White oak is also used for furniture, flooring, pallets, agricultural implements, railroad cars, truck floors, furniture, doors, and millwork.
Durability & sustainability
CITES status: not listed on any CITES Appendix — no international-trade restriction applies to Bur Oak.
Properties
| Specific gravity | 0.64 |
|---|---|
| Janka hardness (side) | 1,370 lbf |
| Density (air-dry, 12% MC) | 44.7 lb/ft³ (716 kg/m³) ovendry-weight basis: 39.9 lb/ft³ |
| Weight per board foot (air-dry) | 3.73 lb |
| Radial shrinkage (green→oven-dry) | 4.4% |
| Tangential shrinkage (green→oven-dry) | 8.8% |
| Volumetric shrinkage (green→oven-dry) | 12.7% |
| T/R ratio (stability indicator) | 2 |
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.