Calculate lumber board feet, build a full cut list, and compare wood species costs — all with a live plank preview.
A board foot is the standard unit of lumber measurement used throughout the North American lumber industry. One board foot equals 144 cubic inches of wood — the volume of a piece of lumber measuring 1 inch thick, 12 inches wide, and 12 inches long. Understanding board feet is essential for ordering lumber accurately, comparing prices between suppliers, and estimating material costs for any woodworking or construction project.
The formula for calculating board feet is: (Thickness in inches × Width in inches × Length in feet) ÷ 12. This can also be written as: Thickness × Width × Length ÷ 12, where thickness and width are in inches and length is in feet. For a single 2×4 that is 8 feet long: (2 × 4 × 8) ÷ 12 = 64 ÷ 12 = 5.33 board feet. For a 1×6 that is 10 feet long: (1 × 6 × 10) ÷ 12 = 60 ÷ 12 = 5.0 board feet.
This formula uses nominal dimensions — the stated size of the lumber — not the actual dimensions. A 2×4 is actually 1.5 inches thick and 3.5 inches wide after milling and drying, but board feet are calculated using the nominal 2 and 4. This is an industry standard that allows consistent pricing regardless of the exact final dimensions. When calculating actual volume (for weight estimation or structural engineering), use actual dimensions. When calculating board feet for ordering and pricing, always use nominal dimensions.
The difference between nominal and actual lumber dimensions is one of the most confusing aspects of lumber purchasing for beginners. When you order a 2×4, you receive a board that is actually 1.5 inches by 3.5 inches. This difference exists because lumber is measured and sold by its rough-sawn green size, but the boards you receive have been dried and planed smooth, which removes approximately 0.5 inches from each face. Understanding actual dimensions is critical for any project where dimensional accuracy matters — fitting boards into a frame, calculating actual span distances, or planning joint dimensions in fine woodworking.
| Nominal Size | Actual Size | BF per Lin Ft | Common Use |
|---|---|---|---|
| 1×2 | ¾" × 1½" | 0.167 | Trim, furring |
| 1×4 | ¾" × 3½" | 0.333 | Shelving, trim |
| 1×6 | ¾" × 5½" | 0.500 | Boards, fencing, casing |
| 1×8 | ¾" × 7¼" | 0.667 | Shelving, siding |
| 1×12 | ¾" × 11¼" | 1.000 | Shelving, wide boards |
| 2×4 | 1½" × 3½" | 0.667 | Wall framing, studs |
| 2×6 | 1½" × 5½" | 1.000 | Floor joists, exterior walls |
| 2×8 | 1½" × 7¼" | 1.333 | Floor joists, rafters |
| 2×10 | 1½" × 9¼" | 1.667 | Floor joists, headers |
| 2×12 | 1½" × 11¼" | 2.000 | Headers, beams |
| 4×4 | 3½" × 3½" | 1.333 | Posts, deck framing |
| 4×6 | 3½" × 5½" | 2.000 | Beams, posts |
| 6×6 | 5½" × 5½" | 3.000 | Heavy posts, columns |
Always add a waste factor to your board foot calculation before ordering lumber. For framing lumber in a simple rectangular structure, a 10% waste factor is generally sufficient — cuts at doors and windows result in offcuts that cannot be reused. For hardwood woodworking projects with complex cuts, joinery, and careful grain matching, waste factors of 20–30% are typical. Very complex figured wood projects with book-matching requirements can run 30–40% waste. Waste factor accounts for end splits that must be trimmed from rough lumber, grain defects you choose to avoid, mistakes during cutting, and inevitable end-use offcuts.
The species of wood you choose for a project affects cost, workability, durability, appearance, and the tools required. Lumber prices change with market conditions, regional supply, and grade, but understanding the general price tiers and properties of common species helps you make an informed material decision before requesting quotes from your supplier.
Southern yellow pine and Douglas fir are the workhorses of construction framing — widely available at every lumber yard and big-box retailer, priced at $3–6 per board foot depending on grade and length. Construction-grade pine (No. 2 or better) is appropriate for framing, sheathing, and structural applications where appearance does not matter. Select or prime pine, with tighter grain and fewer knots, is used for painted trim, furniture, and shelving where a cleaner look is desired. Pine is fast and easy to work with hand tools and power tools, but its relatively soft surface dents easily and it does not accept stain as evenly as hardwoods without pre-conditioning.
Red oak is one of the most common domestic hardwoods used for furniture, cabinetry, and flooring. It has a distinctive open grain pattern and takes stain exceptionally well, making it the classic choice for furniture that will be finished with a dark stain. At $5–10 per board foot for select grades, it is a mid-range hardwood that offers excellent value. White oak is denser, heavier, and more water-resistant than red oak due to its tyloses-filled pores, making it the correct choice for outdoor furniture, wine barrels, and boat building. Both species require carbide-tipped tools for extended tool life.
Hard maple (Acer saccharum) is the standard wood for butcher block countertops, cutting boards, workbench tops, and gymnasium floors due to its exceptional hardness (1450 on the Janka scale) and smooth closed grain that resists bacteria and moisture penetration. It machines to an extremely fine finish but is difficult to work with hand tools. Hard maple is pale creamy white, which makes it ideal for light natural finishes and light stains — it does not absorb dark stains evenly. Priced at $6–12 per board foot for clear grades.
Cedar's natural oils make it naturally resistant to rot, insects, and moisture — giving it the longest outdoor lifespan of any common domestic wood without treatment. Western red cedar is the standard for exterior siding, decking, fencing, and outdoor furniture where appearance matters. It is lightweight, easy to work, and holds finishes well. At $4–8 per board foot, it is a cost-effective choice for exterior applications where pressure-treated pine would otherwise be used. Cedar's aroma also makes it the classic choice for closet lining and hope chests.
Black walnut is one of the most prized domestic hardwoods for fine furniture, gunstocks, instrument backs, and high-end cabinetry. Its dark chocolate-brown heartwood with striking grain variation is immediately recognizable and commands premium prices: $8–20 per board foot for clear grades, more for figured pieces. Walnut is moderately hard (1010 Janka), works beautifully with both hand and power tools, and takes oil finishes particularly well. It is one of the few dark-colored domestic hardwoods, making it a natural choice when a rich dark finish is desired without staining a lighter species.
American black cherry is renowned for its beautiful reddish-brown color that deepens dramatically with light exposure over time, and its fine straight grain that machines to a glass-smooth surface. At $6–15 per board foot, cherry is a premium choice for high-end furniture, cabinets, and interior millwork. One of cherry's most distinctive characteristics is its photosensitivity — freshly milled cherry is pale pink-tan, but it transforms to a rich red-brown within months of light exposure. This aging process is a prized feature that distinguishes genuine cherry furniture from cherry-stained oak or maple.
| Species | Price/BF | Janka | Best Use | Workability |
|---|---|---|---|---|
| Pine (construction) | $3–6 | 870 | Framing, painted trim | Easy |
| Red Oak | $5–10 | 1290 | Furniture, cabinets, floors | Moderate |
| Hard Maple | $6–12 | 1450 | Countertops, butcher block | Moderate |
| Cedar | $4–8 | 350 | Outdoor, siding, closets | Easy |
| Walnut | $8–20 | 1010 | Fine furniture, gunstocks | Good |
| Cherry | $6–15 | 950 | Fine furniture, millwork | Good |