Board Foot Calculator
Board feet, cubic volume and cost for a lumber order.
How it works
A board foot is a volume of 144 cubic inches: one inch thick, twelve inches wide and twelve inches long. With length entered in feet, multiply thickness by width by length and quantity, then divide by 12.
Hardwood is commonly priced from nominal board-foot volume even when surfacing makes the finished board smaller. Match the dimensions to the supplier's pricing basis. Add an allowance for defects, grain matching and offcuts before pricing the order.
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How the Board Foot Calculator works
This board foot calculator combines up to three lumber sizes in one order. It totals net board feet, an order quantity with waste, cubic feet, linear feet, piece count and optional cost.
A board foot is volume, not area
NIST defines one board foot as 144 cubic inches: a board 1 in thick, 12 in wide and 1 ft long, or an equivalent volume. With length entered in feet, the working formula is thickness × width × length × quantity ÷ 12.
For example, ten boards measuring 1 × 6 in and 8 ft long contain 40 board feet. Their total length is 80 linear feet, but linear footage alone says nothing about width or thickness.
Match the supplier's dimension basis
Rough hardwood is commonly quoted from nominal dimensions, while surfacing reduces actual thickness and width. Nominal and actual presets fill both bases quickly, while every dimension remains editable for the stock on the quote.
The allowance covers defects, end checks, grain and color selection, and offcuts. Ten percent is a practical starting point for simple parts; matched panels or defect-heavy stock can require more. The result prices the allowance explicitly instead of silently rounding every board.
FAQ
How many board feet are in a 1 × 6 × 8 board? expand_more
1 × 6 × 8 ÷ 12 = 4 board feet. Ten boards contain 40 board feet before any waste allowance.
Is a board foot the same as a square foot? expand_more
No. A square foot measures surface area. A board foot measures 144 cubic inches of volume, so board thickness is part of the calculation.
Should I use nominal or actual lumber dimensions? expand_more
Use the same basis as the supplier's quote. Nominal dimensions reproduce nominal board-foot pricing; actual dimensions describe the surfaced board's physical volume.