Board Foot Calculator
Enter the lumber thickness, width, length and quantity to get total board feet — the unit hardwood and lumber is sold by.
- Lumber size
- 2×6 × 10 ft
- Without waste
- 200 bf
Use nominal sizes (the named size, like 2×6) for board-foot estimates. Add 15% waste for framing, 20% for hardwood.
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How to calculate it
Enter the lumber thickness, width, length and quantity to get total board feet — the unit hardwood and lumber is sold by.
Source: One board foot = 144 in³ (1 in × 12 in × 12 in). Board feet = (T × W × L ÷ 12) × pieces.
Twenty 2×6 boards, 10 ft long: (2 × 6 × 10 ÷ 12) × 20 = 10 × 20 = 200 board feet. With 15% waste: 230 bf.
Want the full step-by-step walkthrough? Read our How to Plan a Wood Fence: Posts, Pickets & Concrete.
Purchasing & waste guidance
- Lumber is sold by the board foot (1 ft × 1 ft × 1 in) for hardwoods and many dimension sizes.
- Nominal sizes differ from actual — a 2×6 is really 1.5×5.5 in. Use nominal for board-foot estimates.
- Add 15% waste for framing and cuts; 20% for hardwood with selective grain matching.
- Price hardwood by the board foot; softwood framing is often priced per piece.
Assumptions & what’s included
- Dimensions are nominal lumber sizes in inches and feet.
- Waste allowance covers cuts, defects and culling.
- Price is per board foot and optional.
Frequently asked questions
How do I calculate board feet?
Board feet = thickness (in) × width (in) × length (ft) ÷ 12, times the number of pieces. A 2×6 that is 10 ft long is 10 board feet per piece.
How many board feet are in a 2×4×8?
A 2×4×8 is 2 × 4 × 8 ÷ 12 = 5.33 board feet per piece. Multiply by the number of studs to total your order.
Should I use nominal or actual lumber sizes?
Use nominal sizes (the named size, like 2×6) for board-foot estimates and buying. The actual milled size is smaller (1.5×5.5 in) but lumber is priced by the nominal dimension.
Related guides
Step-by-step project guides that use this calculator.