Craft & Making
Board Feet Calculator
Enter timber dimensions to get board feet and an optional cost.
What is a board foot?
Board feet are a North American timber volume measure still quoted by many hardwood suppliers and plans. One board foot is 1 foot × 1 foot × 1 inch of nominal thickness. This calculator converts length, width and thickness into board feet so you can compare prices and estimate project totals. UK buyers working in metric should convert dimensions carefully — mixing inches and millimetres is the usual error. Rough-sawn versus surfaced sizes matter: price may be based on nominal thickness before planing. Related craft costing: 3D print cost for additive jobs, and product profit when you sell finished pieces. Offcuts and kerf waste belong in a separate allowance. Not a structural grading tool. If your merchant sells by the cubic metre, convert board feet to m³ only after you trust the unit trail. Keep a project sheet of board feet per part so a price rise on one species does not surprise the quote.
Worked example
A board 8 ft long, 6 in wide and 1 in thick is (8 × 6 × 1) / 12 = 4 board feet. Ten such boards are 40 board feet. At $6 per board foot the stock costs $240 before delivery — convert to sterling at your own rate if comparing UK metric quotes.
Limits and assumptions
Uses the common nominal board-foot formula. Actual dressed sizes are smaller. Does not grade timber or account for moisture movement.
Frequently asked questions
What is a board foot?
A volume equal to 1 ft × 1 ft × 1 in, or 144 cubic inches.
How do I calculate it?
Board feet = (thickness_in × width_in × length_ft) / 12 for a single board.
Can I use millimetres?
Convert to inches and feet first, or convert the result to m³ separately — do not mix units mid-formula.
Does planing change board feet purchased?
You often pay on nominal size; the finished piece is thinner. Ask how the yard prices.
How should I allow for waste?
Add a percentage for kerf, defects and mistakes on top of the net board-foot total.