Board Foot Calculator (Lumber Volume and Cost)
Enter board size and quantity to get board feet and the cost.
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Board Foot Calculator (Lumber Volume and Cost) by TheCalcTools
How the Board Foot Calculator (Lumber Volume and Cost) works
Board feet = thickness (in) × width (in) × length (ft) ÷ 12.
Multiply by the number of boards.
Add a waste allowance for cuts, defects and mistakes, then multiply by the price per board foot.
The formula
Worked example
Using the default values shown in the calculator:
| Thickness (in) | 1 |
|---|---|
| Width (in) | 6 |
| Length (ft) | 8 |
| Number of boards | 10 |
| Price per board foot | $6.5 |
| Waste allowance | 15 % |
- 1 × 6 × 8 ft = 1 × 6 × 8 ÷ 12 = 4.00 board feet per board.
- 10 boards = 40.00 bf; with 15% waste buy 46.00 bf, about $299.00.
Result:
| Board feet per board | 4.00 |
|---|---|
| Total board feet | 40.00 |
| Board feet to buy with waste | 46.00 |
| Estimated cost | $299.00 |
| Volume (cubic feet) | 3.33 |
Frequently asked questions
What is a board foot?
A board foot is a volume of lumber equal to 1 inch thick, 12 inches wide and 12 inches long, which is 144 cubic inches.
Should I use nominal or actual size?
Hardwood is sold by rough thickness, so use the thickness on the tag. Construction lumber is priced per piece or per linear foot instead.
Sources and further reading
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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.