What is a board foot?
A board foot is lumber volume equal to 1 inch thick × 12 inches wide × 12 inches long, or 144 cubic inches.
Free contractor tool
Board Foot Calculator
Fast lumber math without a spreadsheet. Enter one board or build a full lumber tally with multiple sizes, quantities, waste and price per board foot.
1 BF = 144 in³Thickness × Width × Length(ft) ÷ 12Calculates on your device
Enter your lumber
Fractions work too: try 5/4, 1 1/4, 6 1/2 or 6½.
Quick thickness
Length
ftin
Cost & waste options
Lumber tally
Add different board sizes and keep a running project total.
Add a board to the tally to total multiple lumber sizes.
| Board | Dimensions | Qty | Board feet |
|---|
Exact tally0.00 BF
With waste0.00 BF
Estimated cost—
Which dimensions should I use?
Use the dimensions your supplier prices from. Rough hardwood is commonly sold by nominal thickness such as 4/4 or 8/4 and actual width.
Why add waste?
Extra footage covers defects, grain selection, matching, test cuts and offcuts. Adjust the percentage to fit the project and lumber quality.
About tally rules: This tool uses exact geometric board-foot math. Commercial hardwood grading/tally rules can use specific nominal thickness and rounding conventions, so supplier invoices may differ slightly.