Board Foot Calculator
Work out how many board feet of lumber you need — the unit hardwood is usually priced in. Add each board size and quantity for a total and an optional cost.
Board feet = thickness (in) × width (in) × length (ft) ÷ 12. One board foot is 144 cubic inches — a piece 1 in thick, 12 in wide and 1 ft long. Hardwood is usually priced on its nominal rough-sawn thickness (4/4 = 1 in, 8/4 = 2 in), so enter the nominal size your supplier uses.
4
Total board feet
0.0094
Volume (m³)
Add a price
Estimated cost
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How to use board foot calculator
- 1Choose inches/feet or millimetres/metres.
- 2Enter each board's thickness, width, length and number of pieces.
- 3Add more boards for a full cut list.
- 4Optionally enter the price per board foot to estimate the cost.
About this tool
A board foot is a volume of wood equal to a piece 1 inch thick, 12 inches wide and 1 foot long — 144 cubic inches. The formula is board feet = thickness (in) × width (in) × length (ft) ÷ 12. If the length is in inches, divide by 144 instead.
Example: a 2 × 6 in board 8 ft long is 2 × 6 × 8 ÷ 12 = 8 board feet. Five 1 × 6 boards 10 ft long are 5 × (1 × 6 × 10 ÷ 12) = 25 board feet; at $6 per board foot that's $150.
Hardwood is normally sold by board foot using its nominal rough-sawn thickness in quarters of an inch — 4/4 is 1 in, 5/4 is 1¼ in, 8/4 is 2 in — even after it has been planed thinner, so use the size your supplier prices by. Softwood construction lumber is usually sold by the piece or linear foot instead. Allow extra for defects and offcuts.
Frequently asked questions
Multiply thickness (in) × width (in) × length (ft) and divide by 12. A 1 × 8 in board 6 ft long is 1 × 8 × 6 ÷ 12 = 4 board feet.
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