Trim, moulding and decking are usually sold by the linear foot; rough hardwood by the board foot.
How board feet are calculated
BoardFootCalc multiplies thickness (inches) × width (inches) × length (feet) and divides by 12 for each row, then multiplies by the quantity and adds the rows. Cost is total board feet × your price per board foot. Cubic feet are board feet ÷ 12, and cubic metres use 1 board foot = 0.00236 m³. Nothing is rounded until the result is shown.
Common lumber sizes
| Nominal | Actual (in) | Board feet per 8 ft |
|---|---|---|
| 1×4 | ¾ × 3 ½ | 2.67 |
| 1×6 | ¾ × 5 ½ | 4 |
| 1×8 | ¾ × 7 ¼ | 5.33 |
| 1×12 | ¾ × 11 ¼ | 8 |
| 2×4 | 1 ½ × 3 ½ | 5.33 |
| 2×6 | 1 ½ × 5 ½ | 8 |
| 2×8 | 1 ½ × 7 ¼ | 10.67 |
| 2×10 | 1 ½ × 9 ¼ | 13.33 |
| 2×12 | 1 ½ × 11 ¼ | 16 |
| 4×4 | 3 ½ × 3 ½ | 10.67 |
| 6×6 | 5 ½ × 5 ½ | 24 |
Actual sizes are dry dressed sizes from the American Softwood Lumber Standard (PS 20). Board feet use nominal size, as most lumberyards tally softwood.
Log rules for a 16-foot log
| Diameter (in) | Doyle | Scribner | International ¼″ |
|---|---|---|---|
| 8 | 16 | 31 | 39 |
| 10 | 36 | 55 | 65 |
| 12 | 64 | 86 | 97 |
| 14 | 100 | 123 | 136 |
| 16 | 144 | 166 | 181 |
| 18 | 196 | 216 | 232 |
| 20 | 256 | 272 | 290 |
| 24 | 400 | 403 | 424 |
| 28 | 576 | 559 | 584 |
| 32 | 784 | 741 | 770 |
Doyle: (D − 4)² × L ÷ 16. Scribner: the common formula approximation (0.79D² − 2D − 4) × L ÷ 16, so it can differ by a few board feet from the official Scribner tables. International ¼″: Grosenbaugh's formula. All are estimates of sawn yield, not a measurement of the log's volume.
Tips for buying lumber
Measure the finished parts you need, then add allowance for planing, defects and saw kerf. Rough hardwood is usually tallied by the dealer at the rough size, and widths are often rounded to the nearest inch. Prices per board foot vary widely by species, grade and region, so use your supplier's price.
Frequently asked questions
How many board feet in a linear foot of 2×6?
1 board foot (2 × 6 ÷ 12).
How many board feet in 100 linear feet of 1×4?
33.33 board feet.
How do I convert $ per linear foot to $ per board foot?
Multiply by 12 and divide by thickness × width. $3 per linear foot of 1×6 is $6 per board foot.
Is BoardFootCalc free?
Yes, with no sign-up or ads.
Is my cut list saved?
Yes, in this browser only.