Board Foot Calculator
Calculate board feet of lumber from nominal thickness, width, and length. Standard formula for hardwood and rough lumber ordering.
Assumptions
- Thickness and width are nominal inches (traditional board-foot convention).
- Length is measured along the grain in inches unless a length unit is selected.
- Board foot is a volume measure — 1 BF = 144 in³ of lumber.
- Does not account for planing loss or defect culling.
- Hardwood is often sold by the board foot; softwood dimensional lumber by the piece.
Board feet per piece = (thickness in × width in × length in) ÷ 144. Total = board feet per piece × quantity.1×6 × 8 ft, 10 pieces
- Thickness 1 in, width 6 in, length 96 in. BF per piece = (1×6×96)÷144 = 4 BF. Ten pieces = 40 board feet.
How to measure
Use nominal size from the lumber tag (1×6, 2×8, etc.). Measure length in feet or inches consistently. Count pieces of each size separately.
Common mistakes
- Using actual milled dimensions instead of nominal for board-foot pricing.
- Forgetting to multiply by quantity of identical pieces.
- Mixing up linear feet with board feet.
Frequently asked questions
What is a board foot?
144 cubic inches of lumber — equivalent to a 1×12 board one foot long.
Why nominal vs actual size?
Board-foot pricing traditionally uses nominal dimensions before surfacing.
Does this work for plywood?
Plywood is usually sold by the sheet, not board foot. Use for solid lumber.
Random width hardwood?
Measure each piece or use average width for a batch estimate.