I bought this in a 12-18 month size for my 6 month old grandson and the size is just what I was hoping for. There is room for growth so it will get him through the next several months, but not so big that it looks sloppy. We just have to roll the sleeves up a little and it works great. He is a big baby, not chubby but in good proportion, and is in 12 month clothing. At his six month check-up yesterday he was 28.5 inches long (98th percentile) and 20 pounds (91st percentile). The bright blue looks great with his eye color. Hope this helps when you choose what size to order!
My older grandchildren wear these cozy lined hoodies all winter, as do I. I thought it would be the perfect gift for a new baby getting ready for a winter chill. It does look bigger than I expected for a size 3-6 months size, but it would be a shame to outgrown too quickly. Also, a baby will be layering this jacket over other clothing and sleeves can be easily rolled up if too long. I like the bright green color which not look stained or washed out looking after many washings.