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Board Foot Calculator (Lumber Volume)

Work out board feet — the standard lumber-trade volume unit — from a board's nominal thickness, width, and length, and the total for however many boards you're buying.

Board feet per board
5.333
Total board feet
5.33

How it works

A board foot is a fixed volume unit used throughout the lumber trade to price rough and dimensional lumber regardless of its cross-section: one square foot in area and one inch thick, which works out to exactly 144 cubic inches (12in × 12in × 1in). With thickness, width, and length all converted to inches, board feet = thickness × width × length ÷ 144.

Lumberyards conventionally price by a board's nominal (as-labeled) size rather than its smaller actual milled size — a piece sold as a '2x4' is really about 1.5in × 3.5in once planed — so this takes whatever thickness/width/length you enter at face value, the same way a yard's own board-foot tally works from the labeled dimensions.

Total board feet is just the per-board figure multiplied by however many boards of that exact size you're buying, useful for pricing or ordering a full stack rather than one piece at a time.

FAQ

Should I enter the nominal size or the actual measured size?

Use the nominal size printed on the price tag or quote (e.g. 2in thick, 6in wide) unless your supplier explicitly prices by actual measured dimensions — nominal sizing is the lumber trade's standard convention for board-foot pricing.

Why isn't the result a whole number?

Fractional board feet are completely normal — a 2×4×8' board comes out to exactly 5.33 board feet, for instance. Suppliers typically round up to the nearest whole board foot (or to whatever their own pricing increment is) when quoting a total.

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