Short answer: A 2x4 that is 8 feet long holds 5.33 board feet. The formula is thickness in inches times width in inches times length in feet, divided by 12.
| Size | 8 ft | 10 ft | 12 ft | 16 ft |
|---|---|---|---|---|
| 2x4 | 5.33 | 6.67 | 8 | 10.67 |
| 2x6 | 8 | 10 | 12 | 16 |
| 2x8 | 10.67 | 13.33 | 16 | 21.33 |
| 2x10 | 13.33 | 16.67 | 20 | 26.67 |
| 2x12 | 16 | 20 | 24 | 32 |
What a board foot is
A board foot is a unit of lumber volume equal to a piece 1 inch thick, 12 inches wide and 12 inches long, which is 144 cubic inches. There are 12 board feet in a cubic foot.
Hardwood and rough-sawn lumber are often priced per board foot, while common construction lumber such as 2x4s is usually priced per piece or per linear foot.
Use the nominal size
Board feet are worked out from the nominal size the lumber is sold by. A 2x4 is calculated as 2 inches by 4 inches, even though the finished board measures a little less. This is how mills and yards quote it.
Worked example
Twelve pieces of 2x6 that are 10 ft long hold 10 board feet each, so 120 board feet in total. At $3.50 per board foot that would cost $420.
Use the Board Foot CalculatorEnter your own measurements and get an exact amount.
Frequently asked questions
How do I convert linear feet to board feet?
Multiply the linear feet by the thickness in inches and the width in inches, then divide by 12.
How many board feet are in a 2x6 that is 8 feet long?
Eight. Two times six times eight is 96, and 96 divided by 12 is 8.
Do I use actual or nominal size for board feet?
Use the nominal size. Lumber is bought and priced by its nominal dimensions.
Related calculators
Figures are typical planning values. Material sizes, densities and local requirements vary, so confirm with your supplier before ordering.
Last updated October 11, 2026.