Lumber Board Feet Calculator
Convert nominal dimensional lumber sizes and piece counts into total board feet for ordering, pricing comparisons, and yard tickets across mixed framing packages.
Use nominal size, not dressed (e.g. 2 for a 2x4, not 1.5).
Actual length. For a 92 5/8 in precut stud, use 7.72.
About this tool
Most residential lumber yards price softwood dimensional stock by the board foot, but quote per-piece prices on the rack. When you are pricing a framing package or a deck rebuild, the only way to compare quotes from two yards on a fair basis is to convert your piece count into board feet and divide the total dollars by that number. This calculator does the conversion for one stock size at a time.
Enter the nominal thickness and width in inches (a 2x6 is "2 in × 6 in" for board-foot purposes, even though the dressed dimensions are 1.5 × 5.5), the length in feet, and the number of pieces you need. The result is the total board feet, plus the per-piece figure so you can spot-check.
Board feet is volume by definition: 1 bd ft = 144 cubic inches = a board 12 in × 12 in × 1 in. The formula collapses cleanly into the version contractors carry in their head: thickness × width × length, divided by 12, where thickness and width are inches and length is feet. See the construction methodology page for the standards we follow when sourcing tools like this.
How it works
The board-foot formula is (T × W × L) / 12, where T and W are nominal thickness and width in inches and L is length in feet. Multiply by quantity for the total package.
Why divide by 12? One board foot is a 1-inch-thick board, 12 inches wide, 12 inches long. So a 2x6x8 piece is (2 × 6 × 8) / 12 = 8 bd ft per piece. Nominal dimensions are used because lumber is priced and graded by the size as it left the saw, not the dressed dimension. The National Hardwood Lumber Association (NHLA) Rules document the grading and nominal-sizing conventions; softwood dimensional pricing follows the same conventions for per-bd-ft quotes.
Examples
A 2x6x8 at 100 pieces yields 800 board feet, roughly the framing package for a 12x16 deck with 16-inch on-center joists. Good anchor for per-bd-ft price comparisons between yards.
Precut 92 5/8 inch studs at 2x4. Use the actual length (7.72 ft) not the rounded marketing length. 200 studs is roughly the stud order for a small single-story house.
1x8x12 boards: T1-11 siding battens or face boards. Boards thinner than nominal 2 inches use the same formula with T=1.
When to use
Use this when you are comparing per-board-foot quotes from two lumber yards on the same stock size, sizing the lumber portion of a framing or decking package, or generating a yard ticket. For mixed packages (different sizes in the same order), run the calculator once per size and add the totals. See the concrete yardage calculator for the foundation portion of the same job.
Related concepts
- NHLA Rules : National Hardwood Lumber Association grading and dimension rules
- Nominal vs dressed dimensions
Frequently asked questions
Should I use nominal or actual lumber dimensions?
Nominal. Pricing and grading are based on nominal sizes. A 2x4 stud is priced as 2x4 even though the dressed dimension is 1.5 × 3.5.
How do I handle a mixed lumber order?
Run the calculator once per stock size and add the board foot totals. The dollar comparison across yards is total bd ft × per-bd-ft price.
Is this for hardwood or softwood?
The math works for both. Hardwood is more often sold by the board foot at retail, softwood more often per piece, but the conversion is the same.
Sources
- NHLA Rules for the Measurement and Inspection of Hardwood and Cypress
(primary, accessed Apr 16, 2026)
National Hardwood Lumber Association grading rules, the primary source for nominal-dimension and board-foot conventions applied in both hardwood and softwood pricing.
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