Board Foot Calculator
Rough hardwood is sold by volume, not by the piece. Enter each board size and how many you need — thickness in quarters is fine — and get the total board feet the yard will actually charge you for.
Thickness in inches — 4/4 = 1, 5/4 = 1.25, 6/4 = 1.5, 8/4 = 2. Use the rough nominal thickness the yard quotes.
Optional: pricing
Adds a raw material subtotal — no waste. Use the Lumber Cost & Waste calculator to add a waste allowance and tax.
Formula & how it works
One board foot is 144 cubic inches of wood: a piece one inch thick, twelve inches wide, and twelve inches long.
board feet = thickness(in) × width(in) × length(in) ÷ 144
If length is in feet, use thickness × width × length(ft) ÷ 12. Each board is multiplied by its quantity, and every row is added for the total.
Worked example
Five 4/4 boards, 6″ wide × 8 ft long: 1 × 6 × 96 ÷ 144 = 4 bf each, ×5 = 20 bd ft. Add two 6/4 boards, 8″ × 6 ft: 1.5 × 8 × 72 ÷ 144 = 6 bf each, ×2 = 12 bf. Total 32 board feet.
Buying by the board foot
Figure it on rough thickness
Hardwood is priced on its rough nominal size. A 4/4 board planed smooth measures closer to 13/16 inch, but it is still bought and calculated as a full inch. Enter the nominal thickness the yard quotes so your board-foot count lines up with the price ticket.
Buy extra for cuts and defects
Board feet here are the net wood in your parts. Real boards have knots, checks, and wane you will cut around, and every crosscut and rip loses a little to the saw. Woodworkers typically add 15 to 30 percent on top, which the Lumber Cost and Waste calculator handles when you price the job.
Why not just use linear feet?
Linear feet ignore width, so they only work for uniform stock like trim. Rough boards come in random widths, and a wide plank holds far more wood than a narrow one of the same length. Board feet measure the actual volume, which is why the yard sells hardwood that way.