Board Feet Calculator

in
in
in
$
Total Board Feet40 BF
Board Feet (Each)8 BF
Total Cost$180.00

A board foot is the standard volume unit hardwood lumber is priced in: one square foot of wood that is one inch thick. This calculator converts a board’s thickness, width, and length in inches into board feet, multiplies by how many boards you are buying, and applies a price per board foot to estimate the total lumber cost for a project.

Formula

BF (each) = (T × W × L) / 144; total BF = BF × qty; cost = total BF × price

T
Board thickness in inches
W
Board width in inches
L
Board length in inches
qty
Number of identical boards
price
Price per board foot in dollars

How it works

  1. Enter the rough thickness, width, and length of a single board in inches, along with how many identical boards you need.
  2. The calculator multiplies thickness by width by length and divides by 144 to get the board feet in one board, then multiplies by the quantity for the total.
  3. Enter a price per board foot and the calculator returns the total lumber cost; leave it at zero if you only want the volume.

Worked example

Five rough 8/4 walnut boards, each 2 in thick, 6 in wide, and 96 in long, at $4.50 per board foot.

  1. Board feet each = (2 × 6 × 96) ÷ 144 = 1152 ÷ 144 = 8 BF.
  2. Total board feet = 8 × 5 = 40 BF.
  3. Total cost = 40 × $4.50 = $180.00.

8 board feet per board, 40 board feet total, costing $180.00.

Frequently asked questions

What exactly is a board foot?
A board foot is a volume equal to a piece of wood 12 inches long, 12 inches wide, and 1 inch thick, or 144 cubic inches. It is the unit hardwood is sold by, independent of the board’s actual shape.
Do I use nominal or actual lumber dimensions?
For hardwood sold by the board foot, use the rough (pre-surfaced) thickness such as 4/4 (1 in) or 8/4 (2 in) and the actual width and length, because that is what suppliers charge for.
Why divide by 144?
There are 144 cubic inches in one board foot. Multiplying thickness, width, and length gives cubic inches, so dividing by 144 converts that volume into board feet.
How is the lumber cost calculated?
The calculator multiplies the total board feet across all your boards by the price per board foot you enter. Set the price to zero if you only need the board-foot volume.