What is the Board Foot Calculator?
A board foot is a lumber volume equal to a piece 1 inch thick, 12 inches wide and 12 inches long. Lumber is often priced per board foot.
How to use the Board Foot tool
- Enter Thickness, Width, Length and Quantity.
- The result updates instantly as you type, or press Calculate.
- Use Try an example to see how it works, and Reset to start again.
Formula
Board feet = thickness (in) × width (in) × length (ft) ÷ 12 × quantity.
Worked example
Ten boards of 2 × 6 inches by 8 feet give 80 board feet, costing 360.00 at 4.50 per board foot.
Frequently asked questions
What is a board foot?
A volume of 144 cubic inches of lumber, 1 × 12 × 12 inches.
Do I use nominal or actual size?
Lumber is normally sold by nominal size, so use that for pricing.
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Checked by Calcovate · Formula tested against worked examples · Updated 7 Nov 2026 · How we check our calculators.