Board Foot Calculator
Measurement · Updated July 2026
Enter your lumber's thickness, width, length, and quantity to find the total board feet — the standard unit for pricing hardwood and rough lumber.
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How do you calculate board feet?
Board feet = (thickness in inches × width in inches × length in feet) ÷ 12, multiplied by the number of boards.
How board feet are measured
A board foot is a volume unit — 144 cubic inches — used to price hardwood and rough lumber. The formula is thickness (in) × width (in) × length (ft) ÷ 12. Use the board's actual rough dimensions, not the nominal size, when buying by the board foot.
Board feet vs. linear feet
Linear feet only measure length, so they work for uniform-width trim and framing lumber. Board feet account for thickness and width too, which is why lumberyards price wide or thick hardwood stock this way.
How to use this calculator
- 1Enter thickness and width in inches.
- 2Enter length in feet and quantity.
- 3Read total board feet.
Frequently asked questions
What is a board foot?
A board foot is 144 cubic inches — a piece 1 inch thick, 12 inches wide, and 1 foot long.
How do you calculate board feet?
Multiply thickness in inches × width in inches × length in feet, then divide by 12.
Is a board foot the same as a linear foot?
No. A linear foot measures length only; a board foot measures volume (thickness × width × length).
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