Linear Feet to Board Feet Converter
Convert linear feet of a known-size board into board feet — and compare a per-linear-foot price against a per-board-foot price.
How it works
Board feet = linear feet × (thickness in × width in) ÷ 12
Softwood and trim are often sold by the linear foot, but hardwood is priced by the board foot — so you frequently need to convert to compare. Because a board foot is 144 cubic inches and a linear foot is 12 inches long, the conversion is linear feet times cross-section area (thickness × width, in square inches) divided by 12. The wider or thicker the board, the more board feet you get per linear foot, which is exactly why board-foot pricing exists.
Worked example
You have 8 linear feet of 1″-thick, 6″-wide stock. Cross-section is 1 × 6 = 6 in²; 8 × 6 ÷ 12 = 4.000 board feet. At $4.50 per board foot that is $18.00 — which works out to $2.25 per linear foot for that particular size.
Sources: Board foot — Wikipedia
Frequently asked questions
When would I buy by the linear foot instead?
Dimensional softwood (2×4s, 1×6s) and pre-milled trim come in fixed cross-sections, so they are usually sold by the linear foot. Rough hardwood in random widths is sold by the board foot. Converting lets you compare the two on equal footing.
Does the 12 change with thickness?
No. The divisor is always 12 because a board foot (144 in³) divided by a linear foot (12 in of length) equals 12 in² of cross-section. Thickness and width are what you multiply; the 12 is fixed.
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