How Many Board Feet In a 2x12x12
16.875 board feet
- Actual size: 1.5" x 11.25" (nominal 2x12")
- Length: 12 ft
Methodboard feet = (thickness x width x length in feet) / 12, using the ACTUAL dressed dimension.
Using the nominal 2x12" number instead of the actual dimension would overstate this by a meaningful margin — see /reference/nominal-vs-actual-2x4/.
A 12-foot 2x12 contains 16.875 board feet — the largest single board-foot figure among the dimensional-lumber sizes this site tracks, reflecting both the widest common actual width (11.25") and a longer-than-standard 12-foot length in the same piece.
Why this one specifically
2x12 at 12 feet is stair-stringer and long-span beam stock, where the length itself is the reason for reaching for this size rather than a shorter, cheaper piece — a stringer needs to run the full rise of a staircase in one piece, so the board-foot total here is driven as much by the unusually long length as by the wide cross-section.
What moves the number
This figure uses the actual 1.5" x 11.25" dressed dimension; the nominal 2" x 12" would overstate it, consistent with every other dimensional-lumber size on this site. Length is the more unusual variable here specifically — 12 feet is longer than the 8- and 10-foot lengths covered elsewhere, so this figure doesn't share a simple ratio with the shorter 2x12 lengths the way the 8-and-10-foot pairs elsewhere do.
Compare against the 4x4x8 post for a different high-board-foot shape, or the matching weight figure at how much a 2x12 weighs, and run other lengths through the board foot calculator.