Per board: 5.33 board feet
Total for 1 board: 5.33 board feet
Estimated cost: —
How to use this board foot calculator
Enter the thickness and width of the board in inches, the length in feet or inches, and how many boards you need. The calculator shows the board feet in one board, the total board feet for your quantity, and the total cost if you enter a price per board foot. Use the Feet or Inches button to switch the length unit. If you switch units, your entered length is converted so the physical size stays the same.
How to calculate board feet
Board feet equal thickness in inches times width in inches times length in feet, divided by 12. For a 2 by 4 board that is 8 feet long: 2 times 4 times 8 equals 64, and 64 divided by 12 equals 5.33 board feet. One board foot is 144 cubic inches, the volume of a piece 12 inches wide, 12 inches long, and 1 inch thick. Multiply the board feet in one board by the number of boards to get the total.
Nominal vs actual lumber dimensions
Lumber is sold by its nominal size, which is the size before drying and planing. A 2 by 4 actually measures 1.5 inches by 3.5 inches, and a 2 by 6 actually measures 1.5 inches by 5.5 inches. Board feet are always figured from the nominal size, so enter 2 and 4 in the calculator for a 2 by 4, not 1.5 and 3.5. Using the actual size would undercount the board feet and the price.
Board feet for common lumber sizes (8 ft boards)
| Nominal size | Board feet |
|---|---|
| 1 × 4 × 8 ft | 2.67 |
| 1 × 6 × 8 ft | 4 |
| 1 × 8 × 8 ft | 5.33 |
| 2 × 4 × 8 ft | 5.33 |
| 2 × 6 × 8 ft | 8 |
| 2 × 8 × 8 ft | 10.67 |
| 2 × 10 × 8 ft | 13.33 |
| 2 × 12 × 8 ft | 16 |
| 4 × 4 × 8 ft | 10.67 |
Frequently asked questions
How do I calculate board feet?
Multiply thickness in inches by width in inches by length in feet, then divide by 12. For example, a 2 by 4 that is 8 feet long is 2 times 4 times 8 divided by 12, which equals 5.33 board feet.
How many board feet are in a 2 by 4 that is 8 feet long?
A 2 by 4 that is 8 feet long is 5.33 board feet. Ten of them total 53.33 board feet.
Do I use nominal or actual dimensions for board feet?
Use the nominal dimensions, the size the lumber is sold as. A 2 by 4 is figured as 2 by 4 in the formula even though it actually measures 1.5 by 3.5 inches.
How much extra lumber should I buy?
Add about 10 percent extra for cuts, mistakes, and waste. For a project needing 50 board feet, buy about 55 board feet.
What is one board foot?
One board foot is 144 cubic inches of wood, equal to a piece 12 inches wide, 12 inches long, and 1 inch thick.