I purchased the 12mo size for my 4 no old daughter who is in the 95th% of height.  It was big but I don't want to risk her growing out of it before the season ends. Happy with the way it fits her.  It is soft and is easy to fit over her clothes. Diaper changes are easy since this item is easy to unzip and slid off. Kept her warm in 40 degrees with her clothes and a blanket. Adorable design