CalcArcade.

Board Foot Calculator

Enter the thickness and width in inches, the length in feet and how many boards you have. Add a price per board foot to see the cost.

Your numbers

Result

How we calculate it

A board foot is the volume of a board 1 foot long, 12 inches wide and 1 inch thick, which is 144 cubic inches. Board feet = thickness (in) × width (in) × length (ft) ÷ 12, and the total is that times the number of boards.

A 2 by 6 that is 8 feet long is 2 × 6 × 8 ÷ 12 = 8 board feet. Ten of them make 80 board feet, which at 4.50 per board foot costs 360. One board foot is also one twelfth of a cubic foot.

Assumptions and limits

  • Board feet are worked out from the nominal size, such as 2 by 6, and not from the smaller size of the finished board.
  • Prices per board foot differ by species, grade and region, so use a price from your supplier.
  • Some suppliers sell dimensional lumber by the piece or the linear foot. Board feet are mostly used for hardwood and rough lumber.

Frequently asked questions

What is a board foot?

A unit of lumber volume equal to 144 cubic inches, such as a board 1 inch thick, 12 inches wide and 1 foot long.

How do I calculate board feet?

Multiply the thickness in inches by the width in inches by the length in feet, then divide by 12. Multiply by the number of boards for the total.

Do I use the nominal or actual size?

Use the nominal size, which is how lumber is sold. A 2 by 4 is measured as 2 inches by 4 inches even though the real board is about 1.5 by 3.5 inches.

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Worked example (a fixed example using the starting numbers, it does not change as you type)

Inputs: Thickness (inches) = 2; Width (inches) = 6; Length (feet) = 8; Number of boards = 10; Price per board foot = 4.5.

  • Board feet per board 8.00
  • Total board feet 80.00
  • Total cost $360.00
  • Cubic feet of wood 6.67

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Last reviewed: . Formulas and assumptions are described on our methodology page. For information only; not professional advice.