Calculate board feet of lumber from thickness, width, and length. Estimate total board footage for multiple pieces and plan your lumber purchases.
Board feet (BF) is the standard unit of measure for hardwood lumber in North America. One board foot equals a piece of wood 1 inch thick, 12 inches wide, and 12 inches long—or 144 cubic inches of wood. Whether you're buying rough-sawn hardwood from a sawmill, pricing exotic species at a specialty dealer, or estimating material for a woodworking project, knowing how to calculate board feet is essential.
This board feet calculator lets you enter the thickness in inches, width in inches, and length in feet for each piece of lumber, then computes the board footage instantly. You can add multiple pieces with different dimensions and quantities to build a running total, making it easy to create a complete lumber order.
Understanding board feet helps you compare prices across suppliers, convert between different lumber dimensions, and estimate project costs accurately. Sawmills and hardwood dealers price lumber per board foot, so a quick calculation before you buy ensures you know exactly what you're paying for.
Every woodworker, cabinet maker, and framing contractor needs to estimate lumber quantities in board feet. This calculator eliminates mental math errors, handles multiple piece sizes at once, and gives you a running total you can take to the lumber yard. It's especially useful when working with rough-sawn hardwoods priced by the board foot rather than by the linear foot.
Board Feet (BF) = (Thickness″ × Width″ × Length') / 12 Total BF = BF per piece × Quantity Where thickness and width are in inches and length is in feet.
Result: 80 board feet
Each 2″ × 6″ × 10' board contains (2 × 6 × 10) / 12 = 10 board feet. With 8 pieces the total is 10 × 8 = 80 board feet. At $5 per board foot, this order would cost $400.
Board feet remain the universal measurement for trading hardwood lumber. Sawmills, wholesalers, and retail hardwood dealers all price their inventory per board foot, making it essential for anyone purchasing wood in bulk. Softwoods for framing are more commonly sold by the linear foot or per piece, but converting to board feet allows apples-to-apples cost comparisons across species and suppliers.
Prices vary by species, grade, and region. As of 2025, poplar runs $3–4/BF, red oak $5–7/BF, white oak $6–9/BF, hard maple $6–8/BF, cherry $7–10/BF, and walnut $8–15/BF. Exotic species like purpleheart or zebrawood can exceed $20/BF. FAS (First and Seconds) grade commands a premium over #1 Common.
A linear foot measures only length, ignoring thickness and width. A board foot accounts for all three dimensions. A 10-foot board that is 1″ × 6″ contains 5 board feet, while a 10-foot board that is 2″ × 12″ contains 20 board feet—even though both are 10 linear feet long. Always confirm which unit your supplier uses before placing an order.
A board foot is a unit of volume equal to 144 cubic inches of wood. It corresponds to a piece 1 inch thick, 12 inches wide, and 1 foot long. It is the standard pricing unit for hardwood lumber in the United States and Canada.
For rough-sawn hardwood, use the actual measured thickness and width. For dimensional softwood (like framing lumber), the industry uses nominal sizes for board foot calculations, even though the actual dimensions are smaller after drying and planing.
Using nominal dimensions: (2 × 4 × 8) / 12 = 5.33 board feet. Lumber yards typically quote softwood by the linear foot rather than board foot, but the conversion is useful for comparing costs.
The fraction refers to thickness in quarter inches. 4/4 lumber is 4 quarter-inches or 1 inch thick. Similarly, 8/4 is 2 inches thick, 12/4 is 3 inches thick, and so on. This system is standard for hardwood lumber.
Multiply total board feet by the price per board foot. For example, 80 BF of white oak at $6.50/BF costs $520 before tax and delivery. Specialty species like walnut or cherry may run $8–15 per board foot.
For most woodworking projects, add 15–20% for waste from defects, saw kerfs, and mistakes. For framing lumber with fewer defects, 10% is usually sufficient. Complex projects with angled cuts may need 25% or more.
No. One board foot equals 1/12 of a cubic foot (144 cubic inches vs. 1,728 cubic inches). To convert board feet to cubic feet, divide by 12.
Most yards measure the width at the narrowest face, round down to the nearest inch, and use the shortest length. Some premium suppliers average multiple width measurements for a fairer calculation on live-edge or waney-edge boards.