Board Foot Calculator
A 2x4 that is 8 ft long is (2 x 4 x 8) / 12 = 5.33 board feet by its nominal size, so ten of them are 53.33 board feet (0.126 m³). By actual size, 1.5 x 3.5 in, the same ten boards measure 35.00 board feet.
How to use
- Choose US units (inches and feet) or metric (millimeters and meters).
- In US units, say whether the thickness and width you type are nominal (the 2 in 2x4) or actual (the measured 1.5 in).
- Enter thickness, width, length and the number of boards. Enter a price per board foot to get the cost, or leave it empty.
- Read the total board feet, the volume in cubic meters, the figure on the other size basis and the total price.
How it works
Board feet = thickness (in) x width (in) x length (ft) / 12, times the number of boards. One board foot is a piece 1 in thick, 12 in wide and 1 ft long, which is 144 cubic inches or 0.002359737 m³.
For a 2x4 that is 8 ft long, (2 x 4 x 8) / 12 = 5.33 board feet. Ten boards make 53.33 board feet, and at 3.00 per board foot the cost is 160.00.
In metric mode the tool converts millimeters and meters to inches and feet first, so a 50 x 100 mm board 2.4 m long is 0.012 m³ or 5.09 board feet. Volume in m³ = board feet x 0.002359737.
Nominal sizes come from the American Softwood Lumber Standard (NIST PS 20) dressed dry sizes: nominal 1 is 3/4 in, 2 is 1 1/2 in, 4 is 3 1/2 in, 6 is 5 1/2 in, 8 is 7 1/4 in, 10 is 9 1/4 in and 12 is 11 1/4 in. Softwood is usually priced by the nominal board foot, while rough hardwood is priced by the board foot of the thickness stated in quarters, such as 4/4 = 1 in, 5/4 = 1.25 in and 8/4 = 2 in. Mills may round differently, so confirm with your supplier. The tool does not add waste or trim allowance.
Nominal and actual sizes
| Nominal | Actual (in) | BF per 8 ft, nominal | BF per 8 ft, actual |
|---|---|---|---|
| 1 x 4 | 3/4 x 3 1/2 | 2.67 | 1.75 |
| 1 x 6 | 3/4 x 5 1/2 | 4.00 | 2.75 |
| 2 x 4 | 1 1/2 x 3 1/2 | 5.33 | 3.50 |
| 2 x 6 | 1 1/2 x 5 1/2 | 8.00 | 5.50 |
| 2 x 8 | 1 1/2 x 7 1/4 | 10.67 | 7.25 |
| 2 x 10 | 1 1/2 x 9 1/4 | 13.33 | 9.25 |
| 2 x 12 | 1 1/2 x 11 1/4 | 16.00 | 11.25 |
Hardwood thickness
| Quarters | Thickness |
|---|---|
| 4/4 | 1 in |
| 5/4 | 1 1/4 in |
| 6/4 | 1 1/2 in |
| 8/4 | 2 in |
| 12/4 | 3 in |
FAQ
How do you calculate board feet?
Multiply thickness in inches by width in inches by length in feet, then divide by 12. A board 2 in thick, 6 in wide and 10 ft long is 2 x 6 x 10 / 12 = 10 board feet.
How many board feet is a 2x4 that is 8 feet long?
By nominal size it is 5.33 board feet. By its actual size of 1.5 x 3.5 in it is 3.5 board feet. Lumber yards normally sell and quote softwood by the nominal size.
Should I use nominal or actual dimensions?
For softwood dimension lumber use nominal, because that is how it is priced. For rough hardwood use the thickness stated in quarters (4/4 is 1 in). Use actual sizes when you want the real wood volume.
How many board feet in a cubic meter?
One cubic meter is about 423.8 board feet, since a board foot is 0.002359737 m³. One cubic foot is 12 board feet.
How is the total price calculated?
Total price = total board feet x price per board foot. The tool shows no currency symbol, so use the same currency for the price and the result. Leave the price empty to see the volume only.
Does the tool include waste?
No. Add 10% to 20% for cuts, defects and trimmed ends when you buy, or use the cut list optimizer to see how pieces fit on boards or sheets.