Board Foot Calculator
Calculate board feet for lumber from thickness, width, length, and quantity. Instant board foot calculator with cubic feet and cost.
How the calculation works
A board foot is a volume measure used to price hardwood and dimensional lumber: 1 board foot is 144 cubic inches, equal to a 1″ × 12″ × 12″ piece. Hardwood yards almost always quote price per board foot using nominal thickness and width.
Measure thickness and width in inches and length in feet, then enter how many pieces you need. This board foot calculator also converts to cubic feet and multiplies by your mill price so you can compare quotes. For decking by the piece instead of by board foot, use the deck material calculator.
Formula
Worked example
Ten 2×6 boards, each 8 feet long: (2 × 6 × 8 × 10) / 12 = 80 board feet. At $4.50/BF the lumber costs $360.
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Frequently asked questions
How do you calculate board feet?
Multiply thickness (in) × width (in) × length (ft) × number of pieces, then divide by 12.
Is a 2×4 actually 2 by 4 inches?
Nominal 2×4s are typically 1½″ × 3½″. Hardwood is often sold on nominal thickness (4/4, 8/4). Enter the dimensions your yard uses for pricing.
How many board feet are in a 2×6×8?
(2 × 6 × 8) / 12 = 8 board feet per piece.
Board feet vs cubic feet?
12 board feet = 1 cubic foot, because 12 × 144 in³ = 1,728 in³ = 1 ft³.
Does this include waste?
No. Add 10–15% extra board footage for defects, ripping, and mistakes unless the yard already prices surfaced lumber that way.
Results are estimates for informational purposes and are not financial or professional advice.