Board Feet Calculator
Price hardwood the way the lumberyard does — turn a board's thickness, width, and length into board feet, then a total and a cost.
How it works
A board foot is a chunk of lumber 1 inch thick, 12 inches wide, and 1 foot long. The formula multiplies thickness in inches by width in inches by length in feet, then divides by 12.
So a 1-inch board that's 6 inches wide and 8 feet long is one times six times eight over twelve — 4 board feet. Multiply by how many pieces you're buying and you've got the total for the whole stack.
Hardwood is priced per board foot, so pop in the shop's rate and you'll see the estimated cost. It's the quick way to compare a wide short board against a narrow long one at the rack.
Frequently asked questions
What exactly is a board foot?
A volume: 144 cubic inches of wood, the same as a piece 1 inch thick, 12 inches wide, and 1 foot long. Hardwood lumber is sold by it, which is why the yard talks in board feet rather than linear feet.
Do I use rough or finished thickness?
Lumberyards price by the rough, pre-surfaced thickness, so use that — a board planed to 3/4 inch was likely sold as a full 1-inch, or 4/4 in lumber shorthand. Measure or ask before it's dressed.
How is this different from linear feet?
Linear feet only counts length and ignores how wide or thick a board is. Board feet captures the actual volume, so a wide, thick plank costs more per foot of length than a thin, narrow one.
Does this work for softwood and 2x4s?
The math works for any lumber, though softwood framing like 2x4s is usually sold by the piece or linear foot instead. Board feet really shines for hardwood, where it's the standard unit of sale.