Board Feet Calculator

Hardwood and rough lumber are priced by the board foot: a volume equal to a board 1 inch thick, 12 inches wide and 1 foot long (144 cubic inches). Enter the thickness and width in inches, the length in feet, and how many pieces you need.

The result also shows cubic feet (board feet ÷ 12), which helps when comparing against timber priced by volume. Note that board-foot counts use nominal dimensions at the lumberyard — a rough-sawn 2×4 sold as 8 board feet per 8 ft length is counted at its full nominal size even though the finished board measures less.

The formula

Board feet per piece = (Thickness (in) × Width (in) × Length (ft)) ÷ 12

Worked example

A single 2×4 that is 8 ft long contains (2 × 4 × 8) ÷ 12 = 5.33 board feet, about 0.444 cu ft of wood.

The example is pre-loaded in the result panel — press Calculate with your own numbers to replace it.

Frequently asked questions

What is a board foot?

A unit of lumber volume: 144 cubic inches, visualized as a 1 in × 12 in × 1 ft board. Lumberyards tally rough and hardwood stock in board feet regardless of the board's actual shape.

Why does the yard's tally differ from the finished size?

Board feet are calculated from nominal (rough) dimensions before surfacing. A surfaced '2×4' actually measures 1.5 × 3.5 in, but it is sold by the board footage of the rough blank it came from.

How do I price a project in board feet?

Total board feet × price per board foot. Add 15–25% extra for a woodworking project to cover milling waste, defects and grain matching — more for rough stock.

Category: Construction & Home calculators