Lumber Board-Feet Calculator & Size Chart
Board feet = (Thickness in × Width in × Length ft) ÷ 12. A 2×4 = 0.667 bd ft per linear foot (nominal).
| Nominal Size | Actual Size (in) | Board Feet / Linear Foot | Board Feet per 8ft Board |
|---|---|---|---|
| 2×4 | 1.5″ × 3.5″ | 0.667 BF/LF | 5.333 BF |
| 2×6 | 1.5″ × 5.5″ | 1.000 BF/LF | 8.000 BF |
| 2×8 | 1.5″ × 7.25″ | 1.333 BF/LF | 10.667 BF |
| 2×10 | 1.5″ × 9.25″ | 1.667 BF/LF | 13.333 BF |
| 2×12 | 1.5″ × 11.25″ | 2.000 BF/LF | 16.000 BF |
| 4×4 | 3.5″ × 3.5″ | 1.333 BF/LF | 10.667 BF |
| 4×6 | 3.5″ × 5.5″ | 2.000 BF/LF | 16.000 BF |
| 6×6 | 5.5″ × 5.5″ | 3.000 BF/LF | 24.000 BF |
Standards per American Wood Council (AWC) NDS Standards and APA Engineered Wood Association.
Calculation Results
Calculated estimations for your inputs:
📋 Job Bill of Materials (BOM)
Recommended quantities including safety margins:
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Estimated budget ranges based on standard wood commodity indices and retail rates:
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Sources & Governing Codes
- AWC National Design Specification (NDS) for Wood Construction: AWC National Design Specification (NDS) for Wood Construction View Standard
- USDA Forest Products Laboratory Wood Handbook (FPL-GTR-282): USDA Forest Products Laboratory Wood Handbook (FPL-GTR-282) View Standard
Frequently Asked Questions (FAQ)
What is a board foot?
A board foot (BF) is a specialized unit of lumber volume in the US and Canada, representing the volume of a board that is 12 inches wide, 12 inches long, and 1 inch thick (144 cubic inches).
What is the formula for board feet?
Board feet is calculated as: Board Feet = (Thickness in inches × Width in inches × Length in feet) / 12. If length is in inches, divide the product by 144.
What is nominal vs actual lumber size?
Nominal size is the rough-sawn dimension before planning (e.g. 2x4). Actual size is the finished planed dimension (e.g. 1.5" × 3.5"). Board feet is always calculated using nominal dimensions.
Why is board feet calculated using nominal sizes?
Wood is measured and billed based on its rough-cut volume before it is kiln-dried and planed to finished commercial dimensions, transferring drying waste to the pricing standard.
How does moisture shrinkage affect lumber volume?
Green lumber contains high water content. As it dries to standard 15% or 19% moisture content levels, it shrinks in width and thickness by 3% to 5% under ALSC codes.
What is quarter-sawn lumber?
Quarter-sawn wood is cut at a 90-degree angle to the growth rings, creating straight grain lines that resist twisting, warping, and shrinkage better than flat-sawn lumber.
How many board feet are in a standard 2x4 that is 8 feet long?
Board Feet = (2" × 4" × 8') / 12 = 5.33 BF. A bundle of 100 boards contains 533.33 board feet of lumber volume.
How do you calculate lumber volume in metric cubic meters?
Calculate the actual physical dimensions in meters: Volume (m³) = Thickness (m) × Width (m) × Length (m). To convert BF to m³, multiply BF by 0.00236.
What is lumber check and shake?
A check is a longitudinal crack across growth rings caused by uneven drying. A shake is a separation between rings, both of which reduce structural grade rating capacity.
What is the NHLA standard for grading hardwood lumber?
The NHLA grades hardwoods (like oak or maple) based on the percentage of clear, defect-free wood cut yields, ranging from FAS (First and Seconds) to Common grades.
Lumber Sizing Variants & Related Framing Tools
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