Calculate board feet, volume, weight, area coverage, and wall stud counts for 2×6 lumber boards in any unit.
2x6 Formula
This calculator works in three modes. Each mode uses its own formula.
Board feet, volume, and weight of 2x6 boards:
BF = (T * W * L) / 12
Weight = (1.5 * 5.5 / 144) * L * Density
Boards needed to cover an area:
N = ceil( A * (1 + Waste) / ((Wb + G) * Lb) )
Studs in a 2x6 wall:
Studs = ceil(Lw / S) + 1
- BF = board feet of one board
- T = thickness in inches (2 on a nominal basis, 1.5 on an actual basis)
- W = width in inches (6 nominal, 5.5 actual)
- L = length of one board in feet
- Density = lumber density (about 28 to 36 lb per cubic foot for common softwoods)
- N = number of 2x6 boards needed
- A = area to cover in square feet
- Waste = overage allowance as a decimal (0.10 for 10 percent)
- Wb = actual board width in feet (5.5 in = 0.4583 ft)
- G = gap between boards in feet
- Lb = length of each board you buy, in feet
- Lw = wall length
- S = stud spacing on center
In the board feet mode you enter a board length and a quantity. On a nominal basis a 2x6 gives 1 board foot per foot of length, which is the number most lumber yards price against. Switch to the actual basis (1.5 by 5.5 inches) when you want the true milled volume for weight. Weight comes from the actual cross section times the length times the density you set.
In the coverage mode you enter the surface area, or a length and width, and the board length you plan to buy. The calculator divides the covered area by the area one board covers, rounds up, and adds your waste percentage and any gap between boards.
In the wall mode you enter the wall length and stud spacing. The count is the spaced studs plus one for the final end stud. Plates (one bottom and a double top) are added separately as linear footage when that option is on.
2x6 Lumber Reference Values
These values cover the dimensions, board feet, and approximate weight you will use most often with 2x6 stock. Weight assumes kiln-dried softwood near 30 lb per cubic foot and varies with species and moisture.
| Length | Board feet (nominal) | Board feet (actual) | Approx. weight |
|---|---|---|---|
| 8 ft | 8.0 | 5.5 | 13.8 lb |
| 10 ft | 10.0 | 6.9 | 17.2 lb |
| 12 ft | 12.0 | 8.3 | 20.6 lb |
| 16 ft | 16.0 | 11.0 | 27.5 lb |
Stud counts for a single 2x6 wall at common spacings, before plates and openings:
| Wall length | 16 in OC | 24 in OC |
|---|---|---|
| 8 ft | 7 | 5 |
| 12 ft | 10 | 7 |
| 16 ft | 13 | 9 |
Example Problems
Example 1. You buy six 2x6 boards that are 10 feet long and want the board feet on a nominal basis. Using BF = (2 * 6 * 10) / 12 = 10 board feet per board, six boards give 60 board feet. On the actual basis each board is (1.5 * 5.5 * 10) / 12 = 6.875 board feet, or about 41.25 board feet for all six.
Example 2. You are decking a surface that is 10 by 12 feet, which is 120 square feet, using 12 foot 2x6 boards laid tight. One board covers 0.4583 ft times 12 ft = 5.5 square feet. So N = ceil(120 / 5.5) = 22 boards. Add 10 percent waste and you would order ceil(22 * 1.10) = 25 boards.
Frequently Asked Questions
How many board feet is a 2x6? On the nominal basis used for pricing, a 2x6 is exactly 1 board foot per foot of length, so an 8 foot board is 8 board feet. The true milled size (1.5 by 5.5 inches) gives 0.6875 board feet per foot, which is what you use for actual volume and weight.
What is the actual size of a 2x6? A 2x6 measures 1.5 inches by 5.5 inches after it is dried and planed. The 2 by 6 label is the nominal size before milling. Use the actual size for spacing, coverage, and weight, and the nominal size for board-foot pricing.
How many 2x6 studs do I need for a wall? Divide the wall length in inches by the spacing (16 or 24 inches on center), round up, and add one for the end stud. A 12 foot wall at 16 inch spacing needs 10 studs before you add corners, openings, and plates.
