I got 18 months for my 10 month old girl that 22 pounds and 27 inches long.  Anyways, she is wearing 12 moths and a bit chubby so I wanted room to spare and living in Iowa I needed this to go all winter. I still have 3 more months of winter and will be fine. I think it is roomy for a averaged dressed child and warm enough to get out of the car to and from in.  It is warm, I have to pull her arms out in the car or try to not max out the heat or she is sweaty.  In stores I unzip and pull her arms out in the carts and it makes a good barrier between cart and child.  I get allot of compliments on this and how cute it is. I don't suggest as a snow suit for a child to play outdoors in, but awesome for winter coat in stroller or to and from car and destination.