Did you every go to a lumber yard and stand wondering why 2 pieces of wood look the same but one is much cheaper. The reason is wood grading. Wood grades describe to you how good a board is, and in turn help you decide which one is best for your particular project. If you can make sense of these grades, you can select the right wood and not overpay.
This guide breaks down the grades of wood using clear and to the point language that even a novice can understand it.
What Are Wood Grades?
Wood grades are used to classify lumber. Those grades are based on how many defects a board has and how serious they are. You might expect there to be knots, cracks, splits, bends and bark edges, as well as some small holes.
Higher-grade wood is more defect-free and expensive. Lower-grade wood contains more defects but is less expensive. Expensive grades are ideal for furniture and visible work, while lower grades are suitable if the wood is to be painted or used in framing or hidden applications.
Who Sets Wood Grades?
Different organizations control wood grading rules.
Hardwoods like oak, maple, and walnut are graded by the NHLA. Softwoods like pine, fir, and cedar are graded by groups such as the WWPA.
Inspectors usually judge boards that are at least six inches wide and around eight feet long. Most of the grading is based on the best face of the board, not the worst one.
Hardwood Grades Explained
Hardwoods are graded mainly for appearance, not strength. This makes them ideal for furniture and decorative projects.
FAS (Firsts and Seconds)
FAS is the highest hardwood grade. These boards are mostly clear, with very few knots or defects. Around ninety percent of the wood is usable. FAS lumber is commonly used for tables, cabinets, and fine furniture, but it is also the most expensive option.
Select Grade
Select grade wood is slightly lower than FAS. It allows small defects but still looks clean and attractive. It is often used for visible furniture parts and costs less than FAS.
#1 Common
#1 Common wood allows visible knots and minor cracks. About half to two-thirds of the board is usable. This grade offers excellent value and is widely used for cabinet sides, shelves, and furniture parts that are not always in direct view.
#2 Common
#2 Common lumber contains more knots and defects. It is suitable for hidden areas or rustic designs but is not ideal for fine furniture.
#3 Common and Industrial Grades
These grades have heavy defects and are mainly used for pallets, crates, or workshop jigs. They are usually avoided for finished furniture unless a rough or distressed look is desired.
Character Grade Wood
Character grade is not an official grading term. It is used for boards with visible knots and natural marks that add a rustic or reclaimed appearance. This type of wood is popular for barn doors and farmhouse-style furniture.
Softwood Grades Explained
Softwoods are graded mainly for strength and structural use rather than beauty.
Select Structural
This is the highest softwood grade. It has straight grain and very few defects. It is often used for exposed beams and decorative structural work.
No. 1 and No. 2 Grades
No. 1 and No. 2 grades are commonly used for framing and construction. No. 2 is the most widely available and allows small knots without reducing strength.
No. 3 and Economy Grades
These grades contain many defects and are used for rough or temporary work. Economy grade is the cheapest and is often used for sheathing or packaging.
Appearance Grades
Some softwoods are sold under appearance grades such as C-Select. These boards are smooth and mostly free of knots, making them suitable for wall paneling and interior trim.
What Do S2S and S4S Mean ?
S2S means the board is surfaced smooth on two sides. S4S means all four sides are smooth. Rough-sawn lumber is cheaper but needs planing before use.
How Wood Is Graded
Inspectors focus on the best face of the board and measure how much clear wood can be cut from it. They also check the type of knots, cracks, and warping. Boards with serious bends or twists lose grade quickly.
Moisture content is also important. Wood for indoor use should have a moisture level between eight and twelve percent. Wet wood can warp after installation.
Understanding Board Foot Pricing
Wood is usually priced by board feet. A board foot is a unit of volume equal to one inch thick, twelve inches wide, and twelve inches long.
For example, a board that is one inch thick, twelve inches wide, and twelve feet long equals twelve board feet.
Reading Lumber Yard Labels
A label such as “Red Oak FAS 4/4 S2S” means the wood is red oak, graded FAS, about one inch thick, and surfaced on two sides.
Short or narrow boards are often cheaper but may limit how you can use them.
Choosing the Right Grade for Your Project
Fine furniture looks best when made from FAS or Select grade hardwoods. Cabinets often use high-grade wood for doors and lower grades for box parts to save money. Outdoor decks usually work well with No. 2 pressure-treated pine. Workshop furniture and jigs can be made from low-grade or industrial lumber.
Mixing grades within one project is a smart way to reduce cost without sacrificing appearance.
Common Mistakes to Avoid
Many buyers pay for high grades where they are not needed. Others forget to check moisture content or fail to inspect both sides of the board. Always remember that nominal sizes are larger than actual sizes, such as a 2×4 being smaller than its name suggests.
Final Advice
Wood grades are not meant to confuse you. They exist to help you buy the right wood for the right job. Use higher grades where appearance matters and lower grades where strength or cost is more important. When you understand wood grading, you shop smarter and build better projects.
Frequently Asked Questions: Wood Grades Explained
What’s the top grade for fine furniture like tables?
FAS (First and Seconds) rules—90% defect-free on the best face, perfect for oak or cherry panels where grain shines without knots stealing the show.
How does FAS differ from Select hardwood grades?
FAS demands larger clear areas (4×5′ minimum on 8′ boards) with stricter defect limits; Select allows slightly more minor knots but still yields premium 83% clear wood for doors or moldings.
Can I use #1 Common or #2 for visible projects?
Absolutely for rustic vibes—sound knots up to 1/3 width add character to shelves or barn doors; plane smooth and epoxy-fill for cabinets on a budget.
What’s the difference between hardwood and softwood grades?
Hardwoods (oak, maple) grade for beauty and figure (FAS to Industrial); softwoods (pine, fir) prioritize strength for framing (Select Structural to No. 3), with appearance grades like C-Select for paneling.
How do you calculate board feet for pricing?
BF = (thickness in inches x width x length) / 12—a nominal 1x12x12′ oak = 12 BF; at $8/BF, that’s $96, but trim defects and pay for actual yield.
Does kiln-drying affect wood grades?
No—grading happens pre-dry; kiln caps moisture at 8-12% to fight warp, but green lumber risks twists that dock quality post-cut.
Are wood grades the same everywhere?
Close—NHLA sets U.S. hardwood standards, WWPA softwoods; Europe uses similar metrics but tweaks defect tolerances slightly.
Quartersawn vs flatsawn: Does grade change?
Grading ignores cut pattern, but quartersawn resists cupping and amps ray flecks—grab FAS quartersawn oak for tabletops that stay flat and pop.
How to spot fake or upgraded grades at the yard?
Flip boards, check backs for hidden knots or wane—true FAS shows 90% clear on best face; measure usable footage yourself.
What’s S4S or S2S mean on lumber tags?
S4S (surfaced four sides) smooths all edges ready-to-use; S2S hits two sides—buy rough-sawn (S2S) for custom planing to save cash.
