Board Feet Calculator

Board feet 101. 1 board foot = 144 cubic inches = 1" × 12" × 12". Standard wholesale pricing unit for rough-sawn and hardwood lumber. Common quarter-thicknesses: 4/4 (1"), 5/4 (1¼"), 6/4 (1½"), 8/4 (2"), 12/4 (3"), 16/4 (4"). When buying rough-sawn, the nominal thickness includes some you'll lose to milling — figure about ⅛" loss per face when planning, so 4/4 yields ¾" finished.

Tips for the lumber yard. Rough-sawn boards sold by board foot will have actual widths (the 6" wide board really is ~6"). Dimensional lumber (2x4s, 2x6s) sold at home centers is sold by length, with nominal dimensions that are smaller than actual (a 2x4 is really 1½" × 3½"). For dimensional lumber, board feet calculation uses the NOMINAL size (2 × 4 × length / 12) — that's the convention even though it overstates actual volume.