Board Foot Calculator
A board foot is a lumber volume of 144 cubic inches: a board 1 inch thick, 12 inches wide and 12 inches long. Choose nominal dimensions for a nominal lumber tally or measured dimensions for actual geometric volume; the calculator uses exactly what you enter. It does not infer dressed dimensions or grading rules.
Calculation result
Board feet = thickness (in) × width (in) × length (ft) × pieces ÷ 12. Cost = board feet × price per board foot.
Primary source: Penn State Extension: board foot = 144 cubic inches. NIST SP 811 conversion factors supplies the unit definitions.
Worked example: Three boards, each 1 in × 6 in × 8 ft: 1 × 6 × 8 × 3 ÷ 12 = 12 board feet. At 4 monetary units per board foot, cost = 48. Two boards 2 in × 12 in × 6 ft total 24 board feet.
How to use this tool
Enter thickness, width, length and a positive whole piece count. Add sizes to sum a list. Optional prices use one common currency; a total cost appears only when every row has a price, while priced rows always have a subtotal.
Frequently asked questions
Should I enter nominal or actual dimensions?
Choose the dimensions needed for your tally and label them accordingly. Nominal and dressed lumber sizes can differ. This calculator does not adjust them automatically.
Can I add several sizes and prices?
Yes. Add up to 100 rows. Each row returns board feet and optional cost. With missing prices the calculator shows a priced subtotal and leaves the full cost unavailable.
Is this calculator free and private?
Yes. Arithmetic runs on your device. Your entries are not uploaded or saved to browser storage, and no sign-up is needed.