Pehaps it shrinks when washing? Try that first, and if it`s still big I would recommend finding another that is tighter on you and it`s hard to say really, as long as it`s black, shows no logos and is tight anything goes. A lot of Troopers recommend a two-piece, I have a one-piece and very happy with that. Any compression suit would work. The undersuit I have I bought on ebay - just search for stormtrooper undersuit