Lumber is sold two ways, and mixing them up leads to ordering the wrong amount.
Linear feet
Linear feet measure length only, ignoring width and thickness. Trim, moulding and dimensional lumber bought by the piece are usually counted in linear feet. If you need 40 feet of baseboard, that is 40 linear feet regardless of its profile.
Board feet
A board foot is a volume: 1 inch thick, 12 inches wide and 1 foot long, which is 144 cubic inches. Rough and hardwood lumber is often priced per board foot. Multiply thickness in inches by width in inches by length in feet, then divide by 12. A 2 by 6 board 8 feet long is 8 board feet.
Calculate board feet. Board Foot Calculator →
Common questions
How do I calculate board feet?
Multiply thickness in inches by width in inches by length in feet, then divide by 12.
Is board foot a length or a volume?
A volume. One board foot is 144 cubic inches.
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