Board feet, pieces from linear feet, and cost
Enter your lumber's nominal dimensions and length, and this calculator computes board feet per piece, how many boards you need to cover a given run of linear feet, and the total cost. It uses nominal dimensions (e.g., a "2×4"), which is how lumber is both sold and priced by the board foot.
For 100 linear feet of 2×4 in 8-foot lengths: each board covers 8 linear feet, so pieces = ceil(100 ÷ 8) = 13 boards. Board feet per board = 2 × 4 × 8 ÷ 12 = 5.33 BF, so 13 boards = 69.3 board feet total. At $6 per board, that's $78 plus tax.
A 2×4 actually measures 1.5" × 3.5" after milling and drying. Board feet and lumber pricing use the nominal size, but always use actual dimensions when calculating framing spacings, spans, or finished openings.
What is a board foot? A volume unit equal to a piece 12" × 12" × 1" thick — 144 cubic inches. Hardwood is priced per board foot; dimensional softwood is usually priced per piece.
How many board feet in a 2x4x8? 2 × 4 × 8 ÷ 12 = 5.33 board feet.
How do I estimate framing lumber for a wall? One stud per linear foot of wall at 16" on-center (plus plates), so a 12 ft wall needs about 10–12 studs plus top and bottom plates.
Should I add waste? Yes — add 10–15% for cuts, culls, and mistakes on any framing or trim order.