Bought this for my 7 month old son for Halloween, it was absolutely adorable (I'm sure he'll disagree when he's a teenager and I'm showing the pictures to all of his friends). He weighs 22 lbs. and is about 29" long, based on other reviews I got the 12-18 month size, it was a little big on him and I would have liked to see how the next size down fit but there wasn't time. The legs and arm cuffs were elastic so it wasn't a problem and they stayed put, he looked so adorable and we got tons of compliments. I would definitely buy this again!