Board Feet Calculator
Enter a board's thickness, width, length, and how many you need to calculate total board feet — the standard volume unit hardwood and dimensional lumber is priced by.
Total board feet
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Enter your board dimensions to calculate.
How the Board Feet formula works
The board foot formula:
Board feet (per board) = (Thickness in × Width in × Length ft) / 12 Total board feet = Board feet per board × Quantity
Step-by-step calculation
- Multiply the board's thickness (inches) by its width (inches) by its length (feet).
- Divide by 12 to convert to board feet, the standard unit (equivalent to a 1×12×12-inch board).
- Multiply by the number of boards needed for your total order.
Worked example
10 boards, each 2 inches thick, 6 inches wide, and 8 feet long: Board feet per board = (2 × 6 × 8) / 12 = 8. Total = 8 × 10 = 80 board feet.
Frequently asked questions
Why is lumber priced in board feet instead of just length?
Board feet accounts for all three dimensions — thickness, width, and length — so it reflects actual wood volume, which matters since a thick, wide board uses far more material than a thin one of the same length.
Does nominal lumber size (like a '2×4') equal its actual dimensions?
No — a '2×4' is actually about 1.5 × 3.5 inches after milling and drying. For board-foot calculations on finished dimensional lumber, use the actual measured dimensions, not the nominal name.