A:Answer If you have aluminum windows, will be a snug fit. And that's if the sash and sill will accept the top and bottom bar of the A/C cabinet. If wood, maybe. Sills vary from window to window. And you should add 11/2in for the top and bottom bar of the cabinet. Some wood windows are just made that way. You may consider one size smaller. I wanted 10K, but had to settle for 8K because of window size. Bought two, and have no complaints.