Board Foot Calculator
Calculate board feet from thickness, width, length, quantity, and the price quoted by your lumber supplier.
Estimated stock cost: $240.
What the calculator returns
Total board feet and a straight-line stock-cost estimate.
Method and limits
A board foot is a volume equal to 144 cubic inches. The calculator uses the dimensions you enter, so decide whether your supplier prices rough nominal stock or measured stock before comparing the output with an invoice.
The result does not add milling, defect, color-match, or joinery allowance. Those belong in the quantity or a separate purchasing allowance that matches how selectively you need to cut the boards.
Board-foot examples with the arithmetic exposed
Use thickness and width in inches and length in feet. The example cost column uses $6.50 per board foot only to demonstrate the calculation; replace it with the supplier's current price.
| Rough dimensions | Quantity | Board feet | Example cost |
|---|---|---|---|
| 4/4 × 6 in × 8 ft | 1 | 4.00 | $26.00 |
| 8/4 × 8 in × 10 ft | 2 | 26.67 | $173.33 |
| 6/4 × 10 in × 6 ft | 3 | 22.50 | $146.25 |
Board Foot Calculator questions
What is the board-foot formula?
Multiply thickness in inches by width in inches by length in feet, divide by 12, then multiply by quantity.
How many board feet are in a 1 × 6 × 8 board?
Using a full 1-inch thickness, the result is 1 × 6 × 8 ÷ 12 = 4 board feet. A surfaced board may measure less, so confirm whether the seller prices nominal rough size or actual measured size.
Does a board-foot estimate include waste?
No. The calculator returns entered wood volume. Add a separate purchasing allowance for defects, milling, color matching, joinery, and project risk.