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Board Foot Calculator

A board foot calculator works out the volume of lumber you're buying — the unit hardwood is priced in. Enter a board's thickness, width and length, how many pieces, and (optionally) the price per board foot, and it returns the total board feet and what it will cost.

Your measurements

Result

It's the tool every woodworker and trim carpenter needs at the lumberyard, because boards are sold by volume, not by the piece. Adding the price turns it into a quick cost check at the rack.

How it is calculated

Board feet per piece = thickness (in) × width (in) × length (ft) ÷ 12. Multiply by the number of pieces for the total. One board foot is 144 cubic inches (e.g. 1 in × 12 in × 12 in). Rough lumber is measured at its full nominal size.

Steps

Enter the board thickness in inches (4/4 rough = 1 in).
Enter the width in inches and length in feet.
Enter how many identical pieces you're buying.
Optionally add the price per board foot to get a total cost.
Read the total board feet (and cost).

Worked example

Ten boards that are 1 in × 6 in × 8 ft each are 4 board feet apiece, so 40 board feet total. At $5/bd ft that's about $200.

Common questions

What is a board foot?

A volume of lumber equal to 144 cubic inches — for example a piece 1 inch thick, 12 inches wide and 12 inches long.

How do I calculate board feet?

Thickness in inches × width in inches × length in feet ÷ 12, times the number of boards. The calculator does it for any size.

Why is hardwood sold by the board foot?

Because boards come in random widths and lengths; pricing by volume is fairer than by the piece. Softwood framing is usually sold by the piece instead.

Nominal or actual size?

Use the size you're billed for. Rough hardwood is measured at full ('4/4' = 1 in); surfaced lumber may be billed at nominal size — check with the yard.