📏 Board Foot Calculator
Enter a board’s thickness, width and length to get its board feet — and the total (and cost) for any number of boards.
Total board feet
40 bf
Per board
4 bf
Total cost
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Board feet = thickness(in) × width(in) × length(ft) ÷ 12. A board foot is 144 in³ of wood. 🔒 In your browser.
How the board foot calculator works
A board foot is 144 cubic inches of wood — a piece 1 inch thick, 12 inches wide and 1 foot long. The formula is (thickness × width × length in inches) ÷ 144, or (thickness_in × width_in × length_ft) ÷ 12. Multiply by the number of boards, and by the price per board foot for the cost.
Board feet measure volume, so a thicker board of the same face size counts as more. Hardwood is usually priced per board foot; softwood is often sold by the linear foot or piece.
Frequently asked questions
How do I calculate board feet?
Board feet = (thickness × width × length, all in inches) ÷ 144. A 1 × 6 board that’s 8 ft (96 in) long is 1 × 6 × 96 ÷ 144 = 4 board feet.
What is a board foot?
A unit of lumber volume equal to 144 cubic inches — nominally a board 1 inch thick, 12 inches wide and 1 foot long. It’s the standard way hardwood is sold in North America.
How is board foot different from linear foot?
A linear (running) foot measures length only; a board foot measures volume (thickness × width × length). Two boards of the same length but different widths have different board feet.
Should I use nominal or actual dimensions?
For rough (unplaned) hardwood, use the actual thickness (often quoted in quarters, e.g. 4/4 = 1 in). For dimensional softwood, note that nominal sizes (2 × 4) are larger than actual (1.5 × 3.5 in).
How do I work out the cost?
Multiply the total board feet by the price per board foot. Enter a price and the tool shows the total cost.