Board Feet Calculator
Example: Board thickness: 1 in · Board width: 6 in · Board length: 8 ft · Number of boards: 10 boards · Price per board foot: 6 $
| Total board feet | 40 |
| Board feet per board | 4 |
| Total cost | $240 |
Worked example
Take ten boards that are 1 inch thick, 6 inches wide, and 8 feet long. Board feet per piece is (thickness x width x length-in-inches) / 144 = (1 x 6 x 96) / 144 = 4 board feet. Ten boards is 40 board feet, and at $6 per board foot that is $240 of lumber. Notice the length went into the formula in inches (8 ft x 12 = 96 in), which is the step most people miss.
Frequently asked questions
What exactly is a board foot?
A board foot is a unit of volume equal to 144 cubic inches, the same as a board 1 inch thick, 12 inches wide, and 1 foot long. Because it measures volume, a thicker or wider board contains more board feet even at the same length, which is why hardwood is sold this way.
Do I use the rough or the finished thickness?
Rough hardwood is usually sold and priced on its rough, nominal thickness in quarters (4/4 means 1 inch, 8/4 means 2 inches), and that is the number to enter here. You lose some thickness when you plane it smooth, but you pay for the rough size.
Why is my lumber priced per board foot and not per piece?
Board-foot pricing lets a mill charge fairly for boards of wildly different sizes from the same species. A wide, thick plank simply contains more wood than a thin, narrow one, and board feet capture that. Softwood dimensional lumber is often sold per piece instead, so this tool is mainly for hardwood.
Should I buy extra board footage?
Yes, plan for defects, snipe, and layout waste. A common rule is to add 15 to 30% over your finished requirement for rough hardwood, more for narrow or highly figured stock. Multiply your net board feet by that factor before ordering.