I had one of these already and wanted a smaller size for my new baby. I got the six month size and it was as long as a 12 mth size! My kids are small but still-too big. It's a great snowsuit though-warm but not so heavy they boil in the car or under a blanket. Excellent up to at least -20 C if baby is in a sled/stroller, -10 C if active. Love it in a small size.