Board Foot Calculator
Calculate Board Feet
Common Lumber Sizes — Board Feet Reference
Board feet for standard lumber sizes at common lengths. Nominal dimensions are used for board foot calculations at most lumberyards.
| Nominal Size | 6 ft | 8 ft | 10 ft | 12 ft | 16 ft |
|---|---|---|---|---|---|
| 1 × 4 | 2.00 | 2.67 | 3.33 | 4.00 | 5.33 |
| 1 × 6 | 3.00 | 4.00 | 5.00 | 6.00 | 8.00 |
| 1 × 8 | 4.00 | 5.33 | 6.67 | 8.00 | 10.67 |
| 1 × 10 | 5.00 | 6.67 | 8.33 | 10.00 | 13.33 |
| 1 × 12 | 6.00 | 8.00 | 10.00 | 12.00 | 16.00 |
| 2 × 4 | 4.00 | 5.33 | 6.67 | 8.00 | 10.67 |
| 2 × 6 | 6.00 | 8.00 | 10.00 | 12.00 | 16.00 |
| 2 × 8 | 8.00 | 10.67 | 13.33 | 16.00 | 21.33 |
| 2 × 10 | 10.00 | 13.33 | 16.67 | 20.00 | 26.67 |
| 2 × 12 | 12.00 | 16.00 | 20.00 | 24.00 | 32.00 |
| 4 × 4 | 8.00 | 10.67 | 13.33 | 16.00 | 21.33 |
| 6 × 6 | 18.00 | 24.00 | 30.00 | 36.00 | 48.00 |
How Board Foot Measurement Works
A board foot is the standard unit of volume used to measure and price lumber in the United States and Canada, equal to 144 cubic inches of wood. One board foot corresponds to a piece of lumber that is 1 inch thick, 12 inches wide, and 12 inches long. According to the National Hardwood Lumber Association (NHLA), the board foot has been the industry-standard measurement for hardwood lumber transactions since the organization's founding in 1898, and it remains the universal pricing unit at hardwood lumber dealers, sawmills, and wholesale distributors across North America.
Unlike linear feet (which measure only length) or square feet (which measure area), board feet capture the full three-dimensional volume of a piece of wood. This makes it the fairest method for pricing boards of varying widths and thicknesses, since a 1x6 and a 2x12 of the same length contain very different amounts of usable wood. The U.S. hardwood lumber industry moves approximately 10-12 billion board feet annually, with prices varying significantly by species, grade, and availability. Understanding board feet is essential for accurate project budgeting, whether you are building furniture, cabinetry, or framing structures. You can also use our Cubic Feet Calculator for other volume calculations.
The Board Foot Formula
Calculating board feet uses a simple volume-to-unit conversion. The standard formula is:
Board Foot Formulas:
Board Feet = (Thickness in inches × Width in inches × Length in inches) ÷ 144Board Feet = (Thickness in inches × Width in inches × Length in feet) ÷ 12
The denominator of 144 comes from the definition: 1 board foot = 1" × 12" × 12" = 144 cubic inches. When length is given in feet, the denominator simplifies to 12 because feet already account for one factor of 12.
Worked example: A board that is 2 inches thick, 8 inches wide, and 10 feet long. Board Feet = (2 × 8 × 10) ÷ 12 = 160 ÷ 12 = 13.33 board feet. For 6 identical boards: 13.33 × 6 = 80 total board feet. At $8 per board foot for red oak, this would cost $640.
Key Terms You Should Know
Board Foot (BF or BDFT) is a unit of lumber volume equal to 144 cubic inches. It is the standard pricing unit for hardwood lumber in the U.S. and Canada, enabling consistent comparison across boards of different sizes.
Nominal Dimensions are the labeled sizes of lumber before milling and drying. A "2x4" is nominally 2 inches by 4 inches, but its actual dressed dimensions are 1.5" x 3.5". Most lumberyards calculate board feet using nominal dimensions for standard softwood lumber.
Quarter Sizes describe rough-sawn hardwood thickness in fractions of an inch. 4/4 (four-quarter) is 1 inch thick, 5/4 is 1.25 inches, 6/4 is 1.5 inches, 8/4 is 2 inches, and 12/4 is 3 inches. After planing, a 4/4 board is typically 13/16" or 3/4" thick.
FAS (First and Seconds) is the highest grade in the NHLA hardwood grading system, requiring boards to be at least 83.3% clear (free of knots and defects) on the better face. FAS-grade lumber commands the highest price per board foot.
Linear Foot measures only the length of a board, ignoring width and thickness. Softwood dimensional lumber (2x4s, 2x6s, etc.) is typically sold by the linear foot, while hardwood is sold by the board foot. Use our Length Converter for unit conversions.
Hardwood Lumber Prices per Board Foot
Hardwood lumber prices vary by species, grade, thickness, and region. The following table shows approximate 2025-2026 retail price ranges for FAS-grade 4/4 (1-inch) hardwood lumber, based on data from major hardwood distributors:
| Species | Price per BF (4/4 FAS) | Janka Hardness | Common Uses |
|---|---|---|---|
| Poplar | $3-$5 | 540 lbf | Paint-grade furniture, utility |
| Soft Maple | $4-$7 | 950 lbf | Cabinets, furniture, turning |
| Red Oak | $5-$9 | 1,290 lbf | Flooring, furniture, cabinetry |
| Cherry | $6-$10 | 950 lbf | Fine furniture, cabinetry |
| Hard Maple | $7-$11 | 1,450 lbf | Flooring, butcher blocks, instruments |
| White Oak | $7-$12 | 1,360 lbf | Outdoor furniture, barrels, boatbuilding |
| Walnut | $9-$16 | 1,010 lbf | Premium furniture, gunstocks, accents |
| Teak | $18-$30 | 1,155 lbf | Outdoor furniture, marine, decking |
Prices increase with thickness: 8/4 (2-inch) stock typically costs 20-40% more per board foot than 4/4. Lower grades like No. 1 Common can save 30-50% but contain more knots and defects, requiring more waste when cutting around them.
Practical Examples
Example 1 -- Bookshelf project: You need 6 shelves of cherry lumber, each 1 inch thick, 10 inches wide, and 4 feet long. Board feet per shelf: (1 × 10 × 4) ÷ 12 = 3.33 BF. Total: 3.33 × 6 = 20 BF. At $8 per BF for cherry, material cost is approximately $160. Add 15-20% for waste and milling (about 24 BF total purchase recommended).
Example 2 -- Dining table top: A table top requires a walnut slab 2 inches thick, 36 inches wide (likely glued from multiple boards), and 72 inches long. Board feet: (2 × 36 × 72) ÷ 144 = 36 BF. At $12 per BF for walnut, the raw lumber cost is $432. Including legs and apron, total lumber might be 50+ BF ($600+).
Example 3 -- Deck framing: A deck requires 40 boards of pressure-treated 2x6, each 12 feet long. Board feet per board: (2 × 6 × 12) ÷ 12 = 12 BF. Total: 12 × 40 = 480 BF. While decking is typically sold by the linear foot ($0.50-$1.50 per LF for pressure-treated), knowing the board footage helps compare costs with alternative materials. You can use our Cubic Yard Calculator for gravel and concrete portions of the project.
Tips for Buying and Estimating Lumber
- Always add 15-20% for waste. Hardwood lumber has natural defects, and you will lose material to saw kerfs, jointing, planing, and trimming. A project requiring 30 board feet of finished material should purchase 35-36 board feet of rough lumber.
- Confirm nominal vs. actual pricing. Ask your lumber supplier whether they price board feet based on nominal or actual dimensions. For rough-sawn hardwood, the rough thickness before planing is the standard. For surfaced (S2S or S4S) lumber, some suppliers charge a premium per board foot for the milling service.
- Buy in bulk when possible. Many hardwood dealers offer discounts of 10-20% for purchases over 100 board feet. If you have storage space, buying ahead for multiple projects can yield significant savings.
- Consider lower grades for non-visible parts. No. 1 Common and No. 2 Common grades are 30-50% cheaper than FAS and work perfectly for drawer sides, internal components, and parts that will be painted. Reserve FAS for visible surfaces.
- Use a lumber cut list before shopping. Break your project down into individual parts with dimensions, then calculate total board footage needed. This prevents both over-buying (wasted money) and under-buying (extra trips and potentially mismatched batches). Our Volume Calculator can help with other dimensional calculations.
Nominal vs. Actual Lumber Dimensions
One of the most confusing aspects of lumber for beginners is the discrepancy between nominal and actual sizes. Softwood dimensional lumber is sold using nominal dimensions that are larger than the actual milled and dried dimensions. This has been standard practice since 1964 when the American Lumber Standard Committee established the current sizing conventions. The chart below shows common nominal vs. actual sizes:
| Nominal Size | Actual Size | BF per 8 ft (Nominal) | BF per 8 ft (Actual) |
|---|---|---|---|
| 1 x 4 | 3/4" x 3-1/2" | 2.67 | 1.75 |
| 1 x 6 | 3/4" x 5-1/2" | 4.00 | 2.75 |
| 2 x 4 | 1-1/2" x 3-1/2" | 5.33 | 3.50 |
| 2 x 6 | 1-1/2" x 5-1/2" | 8.00 | 5.50 |
| 2 x 8 | 1-1/2" x 7-1/4" | 10.67 | 7.25 |
| 2 x 10 | 1-1/2" x 9-1/4" | 13.33 | 9.25 |
| 2 x 12 | 1-1/2" x 11-1/4" | 16.00 | 11.25 |
| 4 x 4 | 3-1/2" x 3-1/2" | 10.67 | 8.17 |