Woodworking calculator
Board Feet to Linear Feet Converter
Board feet measure volume and linear feet measure length, so converting between them needs the board cross section. Enter the thickness and width, then a quantity in board feet or in linear feet, and this converter returns the equivalent in the other unit for that exact board profile.
How it works
For a board of fixed thickness and width, board feet and linear feet are directly proportional. Board feet equal the linear feet times the cross-sectional area in square inches, divided by 12. Running the formula backward, linear feet equal the board feet times 12, divided by that same cross-sectional area.
The cross section is what links the two units, which is why you must enter thickness and width. A wide 1 by 12 board racks up board feet quickly per foot of length, while a narrow 1 by 3 needs far more length to reach the same board footage. That difference is exactly why hardwood is sold by board foot and trim is often sold by the linear foot.
Worked example
8 linear feet of 1 × 6 stock: 8 × (1 × 6) / 12 = 4 board feet.
Frequently asked questions
How do I convert board feet to linear feet?
Multiply the board feet by 12, then divide by the cross-sectional area in square inches (thickness times width). The result is the running length in linear feet for that board profile.
How do I convert linear feet to board feet?
Multiply the linear feet by the cross-sectional area in square inches (thickness times width), then divide by 12. The result is the board footage for that length of that board.
Why do I need thickness and width to convert?
Board feet measure volume and linear feet measure length, so the cross section is the missing link. Without thickness and width there is no fixed ratio between the two units to convert with.
Does the conversion depend on the wood species?
No. The board feet to linear feet relationship is purely geometric and depends only on the cross section, not on the species, density, or moisture content of the wood being measured.
Related calculators
Sources
These calculators are for planning and estimation. Engineering results (shelf sag, wood movement) use published average material properties; real boards vary by grade, grain, moisture and defects. Verify load-bearing designs with a professional.