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Lumber / Board Feet Calculator

Calculate board feet for lumber from thickness, width, and length - the standard unit lumber is priced and sold by.

Result

Total Board Feet
4 bf
Board Feet per Board
4
Total Volume
0.0094 m³

About the Board Feet Calculator

Hardwood and dimensional lumber are priced and sold by the board foot, a volume-based unit that has nothing to do with a board's actual length in feet - understanding the difference avoids over- or under-ordering.

How It Works

The calculator multiplies a board's nominal thickness, width, and length together and divides by 12 to get board feet per board, then multiplies by quantity for the total.

board feet = (thickness in × width in × length ft) ÷ 12

Examples

A single board

A 1" × 6" × 8' board is 4 board feet: (1 × 6 × 8) ÷ 12.

Multiple boards for a project

Ten of the same 1x6x8 boards total 40 board feet - useful for getting an accurate lumber yard quote before showing up.

Advantages

  • Handles any thickness, width, length, and quantity combination
  • Optionally estimates total cost if given a price per board foot
  • Uses the standard nominal-dimension convention lumber yards use

Common Mistakes

  • Confusing linear feet with board feet
  • Using actual (milled) dimensions instead of nominal dimensions for board foot pricing
  • Not adding a waste allowance for cutting and defects

Edge Cases to Watch For

  • Board feet is traditionally calculated from nominal (stated) dimensions, not actual dimensions after milling - a nominal 2x4 is actually about 1.5" × 3.5".
  • Hardwood lumber is almost always priced by the board foot; construction-grade softwood dimensional lumber (like framing 2x4s) is more commonly priced per linear foot or per piece instead.
  • Waste from cutting and defects isn't included in this calculation - many woodworkers add 10-20% extra board feet for project waste.

Common Use Cases

  • Getting an accurate lumber yard quote before a project
  • Comparing the cost of different board sizes for the same project
  • Estimating total wood needed for furniture or cabinetry
Written & fact-checked by the Calculateus TeamLast updated August 5, 2026How we verify our formulas

Frequently asked questions

What is a board foot?

A board foot is a volume measurement equal to a board 1 inch thick, 12 inches wide, and 12 inches long (144 cubic inches) - it's the standard unit hardwood and dimensional lumber are priced by, regardless of the actual dimensions of the board.

Do I use nominal or actual lumber dimensions?

Board feet is traditionally calculated from nominal (stated) dimensions, not the slightly smaller actual dimensions after milling (a nominal 2x4 is actually about 1.5" x 3.5") - use nominal size unless you're specifically calculating actual material volume.

Why is a cubic meter figure included?

Board feet is a US-specific pricing unit with no everyday equivalent elsewhere - most other countries price sawn lumber by the cubic meter, so this conversion is included for reference when comparing against metric-priced lumber.

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Conclusion

Board feet is simple multiplication once you know it's a volume unit, not a length one. Use nominal dimensions to match how lumber yards actually price hardwood, and add a waste allowance for anything involving precise cuts.