It is HUGE!! I have an 18 1/2 lb, 26" tall 7 month old baby, so I ordered the 9 month suit
 (according to the size chart - and it seemed right as he barely fits in 9 month carter pjs)  and he was drowning in this suit! I could pull the pants up to his armpits and they still were too long, yet I doubt I could have buttoned the top button if I tried.
super cute, but probably better cut for walkers