Craft & Design
Board Foot
Lumber volume unit: 144 cubic inches. A 1"-thick × 12"-wide × 1-ft-long board is 1 board foot.
View on brothh.comWhat it means
A board foot (BF) is the standard unit of volume for hardwood lumber pricing. One board foot = 144 cubic inches = a nominal 1 in × 12 in × 12 in block.
Formula: BF = (thickness_in × width_in × length_ft) ÷ 12, OR (thickness × width × length_in) ÷ 144. Thickness is nominal for rough lumber (a "4/4" board is 1 in rough, ≈ 0.75 in after milling).
Examples
1 × 6 × 8 ft
(1 × 6 × 8) ÷ 12 = 4 BF
8/4 × 8 × 10 ft
(2 × 8 × 10) ÷ 12 ≈ 13.3 BF
Do
- Buy rough lumber by board foot, milled dimensional lumber by linear foot.
- Always round up when estimating — expect 10-20% waste in cut and rough milling.
Don't
- Confuse board feet with "linear feet" — a 1×12 and a 1×6 differ in BF even at the same length.
History
The board foot dates to 19th-century US sawmills as a way to price irregular rough lumber by the lumber market in Chicago. The name comes from the visualization of a 1 ft × 1 ft × 1 in "board," though any combination that multiplies to 144 cu in qualifies.
Related terms
Calculators that use this
Board Feet
Convert lumber dimensions to board feet and project cost — the standard unit for buying rough lumber.
Wood Project Cost
Add lumber, hardware, finish, and labor into a true project cost — and cost per piece if you are making multiples.
Kerf Allowance
How much material a saw blade eats across multiple cuts — ripping, crosscuts, bandsaw, laser.