Free calculator
Board Foot Calculator
Work out total board feet and lumber cost from thickness, width, length, and quantity. Free, no sign-up. Metric users can convert, but board feet are an imperial measure.
One board foot is a piece 1 inch thick, 12 inches wide, and 1 foot long (144 in³). Nominal vs actual lumber sizes differ, so board-foot pricing usually uses nominal dimensions.
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How to calculate board feet
Board feet = thickness (in) × width (in) × length (ft) ÷ 12 for one piece, then multiply by the number of pieces. A 2×6 at 8 ft is (2 × 6 × 8) ÷ 12 = 8 board feet.
Board-foot pricing usually uses nominal dimensions, so a "2×6" is treated as 2 inches by 6 inches even though the dressed size is smaller. Check how your supplier measures and prices.
FAQ
What is a board foot?
A board foot is a volume of lumber equal to a piece 1 inch thick, 12 inches wide, and 1 foot long, or 144 cubic inches. Lumber is often priced per board foot, especially hardwoods and rough-sawn timber.
How do you calculate board feet?
Board feet = thickness (in) × width (in) × length (ft) ÷ 12, per piece, multiplied by the number of pieces. For example, a 2 × 6 that is 8 ft long is (2 × 6 × 8) ÷ 12 = 8 board feet.
Do I use nominal or actual lumber dimensions?
Board-foot pricing typically uses nominal dimensions (e.g. a '2×6' rather than its actual 1.5 × 5.5 inches). Confirm with your supplier, since some sell rough-sawn lumber by actual size.