Here’s the right way to fold a suit to fit into a carry-on. Lay the jacket flat and button it up, flip over and fold one shoulder over halfway to the middle. Lay the sleeve directly over the fold, repeat with other half. Fold the pants in half lengthwise, then once again. Place the pants on top of the folded jacket shoulders, then fold the jacket in half so the pants are nested inside. When you arrive, unpack and hang.
From:: Packing a suit.