Framing. Framing lumber dimensions The actual size of a 2x4 piece of lumber is 1 ½x3 ½. 2x6 -- 1 ½x5 ½ 2x8 -- 1 ½x7 ¼ 2x10 -- 1 ½x9 ¼ 2x12 -- 1 ½x11 ¼
Sketchup Tutorial, Part 4