How many board feet are in ten 1x10 boards each 12 feet long

• A. 120 board ft
• B. 100 board ft
• C. 80 board ft
• D. 90 board ft

Answer: (B)

Board feet measure lumber by volume, defined as a piece that is 1 inch thick, 12 inches wide, and 1 foot long. To find the total, multiply thickness by width by length, then divide by 12. For a 1x10 board, use nominal dimensions: thickness 1 inch and width 10 inches. Each board, 12 feet long, contributes (1 × 10 × 12) ÷ 12 = 10 board feet. Ten boards give 10 × 10 = 100 board feet. If you used actual dimensions (roughly 3/4 inch thick and 9 1/4 inches wide), you’d get about 6.94 board feet per board, totaling around 69.4, which isn’t one of the choices; this question uses nominal sizes, so 100 board feet is the correct result.