Board Foot Calculator

A board foot is a unit of lumber volume equal to 144 cubic inches—equivalent to a board 12 inches long × 12 inches wide × 1 inch thick. It's the standard unit for buying and selling hardwood lumber in North America. Softwood (like dimensional lumber from home centers) is usually sold by the linear foot, but hardwood from specialty suppliers is priced per board foot.

Board feet = (Thickness × Width × Length) ÷ 144, with all dimensions in inches. Alternatively: (Thickness in inches × Width in inches × Length in feet) ÷ 12. For example, a board 2" thick × 6" wide × 8 feet long = (2 × 6 × 96) ÷ 144 = 8 board feet. Always use actual dimensions, not nominal sizes, for accurate calculations.

Nominal sizes are the names used for lumber (2×4, 1×6, etc.), but actual dimensions are smaller due to drying and planing. A nominal 2×4 actually measures 1.5" × 3.5". A 1×6 is actually 0.75" × 5.5". For rough-sawn hardwood, nominal and actual sizes are typically the same. When calculating board feet, always use the actual measured dimensions.

Lumber prices vary widely by species and grade. Common hardwoods: Poplar $3-5/bf, Red Oak $4-7/bf, Hard Maple $6-9/bf, Walnut $8-14/bf, Cherry $6-10/bf. Exotic woods can exceed $20-50/bf. Prices also depend on board thickness (thicker costs more), grade (FAS vs. #1 Common), and whether it's kiln-dried. Local sawmills often offer better prices than retail suppliers.

Hardwood lumber comes in random widths and lengths—unlike dimensional lumber, which is uniform. Pricing by board foot ensures fair pricing regardless of board dimensions. A 6-foot board and an 8-foot board of equal thickness and width will cost proportionally different amounts. This system lets woodworkers buy exactly what they need and compare prices across different-sized boards.