Linear feet to board feet
Multiply the linear feet by the thickness and the width in inches, and divide by 12. A 2×6 is 2 × 6 ÷ 12 = 1 board foot (BF) in every linear foot, so 100 linear feet of 2×6 is 100 board feet. A 1×6 is half a board foot a foot; a 2×12, two.
| Lumber | Board feet a linear foot |
|---|---|
| 1×4 | 0.333 |
| 1×6 | 0.5 |
| 1×8 | 0.667 |
| 1×12 | 1 |
| 2×4 | 0.667 |
| 2×6 | 1 |
| 2×8 | 1.333 |
| 2×10 | 1.667 |
| 2×12 | 2 |
| 4×4 | 1.333 |
| 6×6 | 3 |
Type the whole run into the length box — 100 for 100 ft — or one board's length and the number of boards beside it. Both come to the same board feet.
These are nominal sizes, the ones a yard bills by. The 2×6 is really 1½ in by 5½ in, so the same 100 linear feet hold 68.75 board feet of wood. The answer prints both.
Buying a run
No yard sells a 100 ft board. The list buys the run in the longest boards it holds, 20 ft: five of them, and six once 10% for cuts and defects is on. Shorter pieces add joints; the list does not plan the cuts, it counts the boards.
A price per linear foot works the same way backwards: choose "per linear foot" under "The price is", and the answer says what that is per board foot and per board.