Hardwood Lumber Guide
Hardwood lumber is used for furniture, cabinetry, flooring, millwork, and fine woodworking projects where appearance and durability matter. This guide covers how hardwood is categorized, graded, sold, and selected.
Hardwood vs Softwood: The Botanical Distinction
The terms hardwood and softwood are botanical, not descriptive of physical hardness. Hardwoods come from angiosperms — deciduous, broad-leaved trees that lose their leaves seasonally. Softwoods come from gymnosperms — conifers that are typically evergreen.
This means balsa (a tropical angiosperm) is technically a hardwood despite being among the lightest, softest woods. Conversely, Southern Yellow Pine is classified as a softwood but is harder and denser than many hardwoods.
| Category | Botanical type | Common species | Typical use |
|---|---|---|---|
| Hardwood | Deciduous (angiosperm) | Oak, Maple, Walnut, Cherry, Ash | Furniture, flooring, cabinets |
| Softwood | Conifer (gymnosperm) | Pine, Fir, Cedar, Spruce, Hemlock | Framing, sheathing, trim |
How Hardwood Lumber Is Sold
Unlike softwood dimensional lumber (sold by the piece or linear foot in standard sizes), hardwood is sold by the board foot — a unit of volume equal to 1 inch thick × 12 inches wide × 12 inches long (144 cubic inches). This lets a dealer sell boards of varying dimensions at a consistent price per unit of volume.
→ What is a board foot? Complete explanation
→ Use the free calculator to figure out how many board feet you need
Hardwood Thickness: Quarter Designations
Hardwood thickness is expressed in quarters of an inch, abbreviated as the number followed by "/4":
| Designation | Nominal thickness | Rough (RGH) | Surfaced one side (S1S) | Surfaced two sides (S2S) |
|---|---|---|---|---|
| 4/4 | 1" | 1" | 15/16" | 13/16" |
| 5/4 | 1¼" | 1¼" | 1 3/16" | 1 1/16" |
| 6/4 | 1½" | 1½" | 1 7/16" | 1 5/16" |
| 8/4 | 2" | 2" | 1 15/16" | 1¾" |
| 10/4 | 2½" | 2½" | 2 7/16" | 2¼" |
| 12/4 | 3" | 3" | 2 15/16" | 2¾" |
| 16/4 | 4" | 4" | 3 15/16" | 3¾" |
Rough lumber (RGH) is sawn but not surfaced — it's the full nominal thickness. Surfaced lumber has been run through a planer, which removes some thickness. Always confirm whether pricing is for rough or surfaced stock.
NHLA Grading System
The National Hardwood Lumber Association (NHLA) sets the grading rules used throughout the North American hardwood industry. Grades are based on the percentage of clear (defect-free) wood that can be recovered from a board, measured in "cuttings."
| Grade | Min. clear face | Min. board size | Notes |
|---|---|---|---|
| FAS (Firsts & Seconds) | 83⅓% | 6" wide × 8' long | Top commercial grade; wide, long boards |
| FAS One Face (F1F) | 83⅓% one face | 6" × 8' | One face meets FAS; back meets No. 1 Common |
| Select & Better (Sel&Btr) | 83⅓% | 4" × 6' | Combines FAS and Sel into one grade |
| No. 1 Common | 66⅔% | 3" × 4' | Good for smaller projects; some knots/defects |
| No. 2A Common | 50% | 3" × 4' | More character; suitable for paint-grade work |
| No. 3A Common | 33⅓% | 3" × 4' | Lower grade; industrial applications |
For fine furniture and cabinetry, FAS or Select grade is typical. For rustic furniture, farmhouse tables, or projects that embrace character wood, No. 1 Common can offer significant cost savings with interesting grain.
Flat-Sawn, Rift-Sawn, and Quarter-Sawn
The angle at which a log is cut relative to the annual growth rings determines both the grain pattern and dimensional stability of the board.
| Cut type | Rings to face | Grain pattern | Stability | Yield | Cost |
|---|---|---|---|---|---|
| Flat-sawn (plain-sawn) | 0–30° | Cathedral/arch pattern | Lower (cups, twists) | Highest | Lowest |
| Rift-sawn | 30–60° | Straight, consistent grain | High | Low | High |
| Quarter-sawn | 60–90° | Straight grain + ray fleck | Highest | Medium | Medium–high |
Quarter-sawn oak is prized for its distinctive medullary ray fleck and superior dimensional stability — it moves significantly less with humidity changes than flat-sawn stock. It's common in Arts & Crafts furniture and mission-style work.
Common Hardwood Species
| Species | Janka hardness (lbf) | Color | Common uses | Relative price |
|---|---|---|---|---|
| Red Oak | 1,290 | Pinkish-red tones | Flooring, cabinets, furniture | $ |
| White Oak | 1,360 | Light brown, gray tones | Flooring, furniture, whiskey barrels | $$ |
| Hard Maple | 1,450 | Creamy white to light brown | Cutting boards, floors, butcher block | $$ |
| Black Walnut | 1,010 | Rich chocolate brown | Fine furniture, gunstocks, veneers | $$$ |
| Black Cherry | 950 | Reddish-brown, darkens with age | Fine furniture, cabinets, millwork | $$$ |
| White Ash | 1,320 | Light brown with olive tones | Tool handles, sports equipment, furniture | $$ |
| Hickory | 1,820 | Tan to reddish-brown | Tool handles, flooring, BBQ wood | $$ |
| Yellow-Poplar | 540 | Pale green to brown (streaky) | Paint-grade furniture, interior trim | $ |
| Hard Maple (figured) | 1,450 | Quilted, curly, birdseye figure | Musical instruments, decorative work | $$$$ |
NHLA Tally Rules for Board Foot Calculation
The NHLA sets specific rules for how hardwood board feet are tallied at the mill:
- Thickness: Measured at the thinnest point on the face, rounded up to the next 1/4-inch increment. Any board thinner than 1 inch (4/4) is tallied as 4/4.
- Width: Measured at the narrowest point; fractional inches are rounded down to the nearest whole inch.
- Length: Measured in whole feet, rounded down to the nearest foot. An 8'11" board is tallied as 8'.
The board foot calculator on this site includes a "Hardwood tally" toggle that applies NHLA rounding rules.
Where to Buy Hardwood Lumber
- Hardwood specialty dealers: The best selection and knowledgeable staff. Look for a local hardwood dealer (NHLA members) for in-person board selection.
- Online lumber retailers: Convenient for small orders. Shipping costs can be significant for heavy, large boards.
- Sawmills: Best prices for large quantities; you may need to green-stack and dry the lumber yourself.
- Big-box stores: Carry a limited selection — typically poplar, oak, and sometimes pine. Boards are pre-dressed to specific dimensions.
- Woodworking clubs and auctions: Opportunity to find figured, unusual, or reclaimed species.
Frequently Asked Questions
What is the difference between hardwood and softwood?
The distinction is botanical, not physical hardness. Hardwoods come from deciduous (broad-leaved) trees like oak, maple, and walnut. Softwoods come from conifers like pine, fir, and cedar. Balsa is technically a hardwood despite being very soft; Southern Yellow Pine is quite hard despite being a softwood.
How is hardwood lumber sold?
Hardwood is sold by the board foot — a unit of volume equal to 144 cubic inches. This differs from softwood framing lumber, which is typically sold by the linear foot or by the piece in standard lengths.
What does 4/4, 5/4, 8/4 mean in hardwood?
These are quarter designations for thickness. 4/4 means 4 quarters = 1 inch nominal (about 13/16" surfaced). 5/4 means 1.25 inches nominal. 8/4 means 2 inches nominal. It is a traditional way to express thickness in the hardwood trade.
What is FAS grade hardwood?
FAS stands for Firsts and Seconds — the top NHLA grade. FAS boards are wide, long, and mostly clear of defects. Below FAS are grades: Select & Better (Sel&Btr), No. 1 Common, No. 2 Common, and below. Higher grade = more clear wood = higher price per board foot.
What is the difference between quarter-sawn and flat-sawn lumber?
Flat-sawn (also called plain-sawn) cuts the log tangentially, producing the cathedral grain pattern common in most lumber. Quarter-sawn cuts at roughly 90° to the growth rings, producing a more uniform straight grain, increased dimensional stability, and distinctive ray fleck in species like oak and maple.