We just finished our back porch and wanted to add a porch swing, but all the ones we were looking at were very expensive! So, I had this brilliant idea to convert our son’s crib to a porch swing. We used our dining room chairs and couch arms as reference as how high to go, 17 inches in the back and 10 inches on the side. We used 1×3 to cap the arm rests and 1×3’s for back support. And to cap off the top. We used 2×4’s to put on the bottom for support and to extend them past each side of the crib and put a hole in it to put the rope to hang it! We had to find the rafters on our covered porch and put two rings to hang it! Check it out!
Dining chair for reference