Board Foot Calculator
Add every board on your cut list, set a waste allowance and a price, and get the total board feet to order, the cost, and the volume. Works for framing lumber and rough hardwood.
By ChiselJobs Team · Updated
Cut List
Use nominal sizes for framing lumber (a 2x4 is 2 x 4) and rough thickness for hardwood (4/4 = 1 in, 5/4 = 1.25 in, 8/4 = 2 in).
Totals
Estimated Cost
Add a price
Linear Feet
8.0 ft
Volume
0.014 m³
Pieces
1
What Is a Board Foot?
A board foot is a unit of lumber volume: a piece 1 foot long, 1 foot wide and 1 inch thick, or 144 cubic inches. It is how hardwood is sold almost everywhere in North America, and how lumber yards price and tally large softwood orders.
Because it measures volume, the same board foot can come in many shapes. A 1 x 12 that is 1 foot long, a 2 x 6 that is 1 foot long, and a 1 x 6 that is 2 feet long are each one board foot. That is what makes board feet useful for comparing prices across different sizes, and confusing when you are used to buying by the piece or the linear foot.
Board Foot Formula
Measure thickness and width in inches and length in feet. If you measure length in inches, divide by 144 instead of 12.
- BF
- Board feet
- T
- Thickness in inches (nominal or rough)
- W
- Width in inches (nominal or rough)
- L
- Length in feet (or inches in the second formula)
One board foot is 0.00236 cubic meters, so about 424 board feet make one cubic meter.
Nominal vs. Actual Size
Framing lumber is sold and tallied by its nominal size, the size before drying and planing. A 2x4 actually measures 1-1/2 x 3-1/2 inches, but a 2x4x8 is still counted as 2 × 4 × 8 ÷ 12 = 5.33 board feet. Enter nominal sizes for dimension lumber.
Hardwood is sold by rough-sawn thickness in quarter inches: 4/4 is 1 inch, 5/4 is 1-1/4 inches, 8/4 is 2 inches. Width and length are measured on each board, because hardwood comes in random widths and lengths. When a yard tallies a bundle, widths are rounded to the nearest inch and lengths are rounded down to the whole foot, so an 8-1/2 foot board counts as 8 feet. If you want to match the yard’s tally, enter the rounded numbers.
Worked Example: Framing Package With 10% Waste
A small wall and floor package needs twenty 2x4x8 studs, six 2x10x12 joists and four 1x6 boards 96 inches long. Add 10% for waste.
- Studs: 2 × 4 × 8 ÷ 12 = 5.33 BF each, × 20 = 106.67 BF.
- Joists: 2 × 10 × 12 ÷ 12 = 20 BF each, × 6 = 120.00 BF.
- Boards: 1 × 6 × 96 ÷ 144 = 4 BF each, × 4 = 16.00 BF.
- Cut list total: 106.67 + 120.00 + 16.00 = 242.67 BF.
- With 10% waste: 242.67 × 1.10 = 266.93 BF.
Worked Example: Rough Walnut for a Tabletop
Three boards of 8/4 walnut are tallied at 7 in x 9 ft, 5 in x 8 ft, and 6 in x 10 ft. The yard charges $14.00 per board foot. No waste is added because the boards are already picked.
- Board 1: 2 × 7 × 9 ÷ 12 = 10.50 BF.
- Board 2: 2 × 5 × 8 ÷ 12 = 6.67 BF.
- Board 3: 2 × 6 × 10 ÷ 12 = 10.00 BF.
- Total: 27.17 BF × $14.00 = $380.33.
Board Feet in Common Lumber Sizes
Board feet per piece, calculated from nominal size.
| Nominal | Actual (in) | 8 ft | 10 ft | 12 ft | 16 ft |
|---|---|---|---|---|---|
| 1x4 | 3/4 x 3-1/2 | 2.67 | 3.33 | 4 | 5.33 |
| 1x6 | 3/4 x 5-1/2 | 4 | 5 | 6 | 8 |
| 1x8 | 3/4 x 7-1/4 | 5.33 | 6.67 | 8 | 10.67 |
| 1x12 | 3/4 x 11-1/4 | 8 | 10 | 12 | 16 |
| 2x4 | 1-1/2 x 3-1/2 | 5.33 | 6.67 | 8 | 10.67 |
| 2x6 | 1-1/2 x 5-1/2 | 8 | 10 | 12 | 16 |
| 2x8 | 1-1/2 x 7-1/4 | 10.67 | 13.33 | 16 | 21.33 |
| 2x10 | 1-1/2 x 9-1/4 | 13.33 | 16.67 | 20 | 26.67 |
| 2x12 | 1-1/2 x 11-1/4 | 16 | 20 | 24 | 32 |
| 4x4 | 3-1/2 x 3-1/2 | 10.67 | 13.33 | 16 | 21.33 |
| 6x6 | 5-1/2 x 5-1/2 | 24 | 30 | 36 | 48 |
Hardwood Thickness: Quarters, Rough and Surfaced
Rough thickness is used for board feet. Surfaced two sides (S2S) is what you get after planing at the yard.
| Quarter | Rough thickness | Surfaced (S2S) | BF per foot of 6" board |
|---|---|---|---|
| 4/4 | 1" | 13/16" | 0.50 |
| 5/4 | 1.25" | 1-1/16" | 0.63 |
| 6/4 | 1.5" | 1-5/16" | 0.75 |
| 8/4 | 2" | 1-3/4" | 1 |
| 10/4 | 2.5" | 2-1/4" | 1.25 |
| 12/4 | 3" | 2-3/4" | 1.50 |
| 16/4 | 4" | 3-3/4" | 2 |
How Much Waste to Add
Every project loses wood to saw kerf, end checks, knots, crooked boards and mistakes. A waste allowance keeps you from making a second trip to the yard. These are common rules of thumb, not fixed numbers.
- Framing with a planned cut list: 10%.
- Decking and siding: 10% to 15%, more with diagonal patterns.
- Hardwood furniture from higher grades (FAS, Select): 15% to 20%.
- Lower hardwood grades (No. 1 and No. 2 Common): 30% or more, since you cut around defects.