Board Foot Calculator
Enter your lumber dimensions and price per board foot to see total board feet and the cost.
| Nominal size | Board feet each | Total |
|---|---|---|
| 1x4 | 2.67 | 2.67 |
| 1x6 | 4.00 | 4.00 |
| 1x8 | 5.33 | 5.33 |
| 2x4 | 5.33 | 5.33 |
| 2x6 | 8.00 | 8.00 |
The board foot formula
Board feet equal thickness in inches times width in inches times length in inches, divided by 144. Because lumber is priced by length in feet, the quick version is thickness times width times length in feet, divided by 12. A 2x8 that is 8 feet long works out to 10.67 board feet.
Nominal versus actual size
Lumber is priced on nominal size, the label on the tag, even though a dressed 2x4 actually measures 1.5 by 3.5 inches. Use the nominal numbers in the calculator to match the price you are quoted. Rough-sawn hardwood is often sold at its true thickness.
Why board feet matter
Hardwood yards quote by the board foot, so knowing the total stops you from overpaying or running short. Buy a little extra on figured or wide stock, since defects and trimming eat into usable length.
Our picks
Questions about this calculator
How do you calculate board feet?
Multiply thickness in inches by width in inches by length in inches, then divide by 144. Or multiply thickness by width by length in feet and divide by 12.
How many board feet is a 2x4x8?
A 2x4 that is 8 feet long is 5.33 board feet. Use nominal 2 and 4 in the formula, not the actual 1.5 and 3.5.
How many board feet is a 1x6x8?
A 1x6 that is 8 feet long is 4 board feet, so five of them are 20 board feet.
Is a board foot the same as a linear foot?
No. A linear foot measures length only, while a board foot also accounts for thickness and width. That is why a wide board costs more per linear foot.
Do I use nominal or actual thickness?
Use nominal size, the number on the price tag, because lumber is priced that way. Actual dimensions are smaller after planing.
How much extra lumber should I buy?
Add 10 to 15 percent for cuts and defects, and more for figured or wide boards where you may need to work around flaws.