Board Feet Calculator
Enter the thickness, width and length of a board and how many pieces you need. The calculator returns board feet per piece and in total, the same volume in cubic feet and cubic meters, and a cost if you add a price.
Last updated November 4, 2026
A "2x4" is about 1.5 x 3.5 in once planed. Enter the size your supplier counts.
Leave blank to skip the cost.
Result
5.33 board feet
| Measure | Value |
|---|---|
| Board feet per piece | 5.33 |
| Total for 1 piece | 5.33 board feet |
| Cubic feet | 0.4444 |
| Cubic meters | 0.0126 |
Lumber is often priced from nominal sizes. Use the thickness and width your supplier measures.
Show the work
Formula: board feet = thickness (in) x width (in) x length (ft) / 12 x pieces; 1 board foot = 144 cubic inches
- Per piece: 2 x 4 x 8 / 12 = 5.333333 board feet.
- Total: 5.333333 x 1 = 5.33 board feet.
- Volume: 5.333333 x 144 = 768 cubic inches = 0.444444 cubic feet.
Result: 5.33 board feet
How board feet are worked out
board feet = thickness (in) × width (in) × length (ft) ÷ 12 × pieces
1 board foot = 144 cubic inches
One board foot is the volume of a board 1 inch thick, 12 inches wide and 1 foot long, which is 144 cubic inches, or one twelfth of a cubic foot. Multiply thickness in inches by width in inches by length in feet and divide by 12.
A board 1 in thick, 6 in wide and 10 ft long is 1 × 6 × 10 ÷ 12 = 5 board feet. Twelve of them make 60 board feet, which is 5 cubic feet. At $4.25 per board foot the cost is $255.
See how we calculate for the formulas, sources and review schedule behind every calculator.
Nominal versus actual size
US softwood is named by its rough size before planing. A nominal 2x4 measures about 1.5 by 3.5 in once planed. Entered as 2 by 4 and 8 ft long, it is 5.33 board feet; entered as 1.5 by 3.5, it is 3.5 board feet.
Lumber is commonly priced from the size your supplier counts, so ask which one they use and enter that size.
Metric input
In metric mode, enter thickness and width in millimeters and length in meters. They are converted with 1 in = 25.4 mm and 1 ft = 0.3048 m, and the price is per cubic meter.
How to use the Board Feet Calculator
- Choose imperial or metric units.
- Enter the thickness, width and length of one piece.
- Enter the number of identical pieces.
- Add a price per board foot (or per cubic meter) if you want the cost.
- Read the board feet and volume, then use Copy, Print or Share.
Worked example
A board 1 in by 6 in by 10 ft is 5 board feet. Twelve of them are 60 board feet, equal to 60 ÷ 12 = 5 cubic feet.
| Pieces | Board feet | Cubic feet |
|---|---|---|
| 1 piece, 2 × 4 in × 8 ft (nominal) | 5.33 | 0.44 |
| 1 piece, 1.5 × 3.5 in × 8 ft (actual) | 3.5 | 0.29 |
| 12 pieces, 1 × 6 in × 10 ft | 60 | 5 |
| 10 pieces, 2 × 6 in × 12 ft | 120 | 10 |
Frequently asked questions
How many board feet are in a 2x4x8?
Using the nominal 2 by 4 in size it is 5.33 board feet. Using the actual planed size of about 1.5 by 3.5 in it is 3.5 board feet.
How many cubic feet are in a board foot?
One board foot is 144 cubic inches, which is one twelfth of a cubic foot, or about 0.0833 cubic feet.
Should I use nominal or actual dimensions?
Use whichever your supplier prices by. Many lumber sellers count board feet from nominal size, so ask before you compare quotes.
Can I calculate several different boards at once?
This calculator handles identical pieces. For mixed sizes, calculate each size separately and add the board feet together.