My bed frame dimensions were 76 wide by 80 length. So that is the inside demension after assembly. My headboard posts were cut to 54" and footboard posts were cut to 24". Headboard panels are 31.5" (14- 6" boards) and footboard panels are 15.5" (14- 6" boards). My posts were made from combining two 2x4s together. I plan on mounting the metal bed frame to the inside of the bed rails. I enjoyed this project greatly.