TLDR; these sleepsacks will do. They are much less expensive than the other popular brands on the market, which is great for how fast our little guy grows out of the very expensive sleep sacks we have bought.For size reference, we purchased an XL. Our little one is 12 months, 25 lbs, and 32 inches long. There is plenty of room in the arms but not too much where he can slip out and it cause problems. There is also plenty of room for him to grow in the length. We’ve had one night in these so far, See full review