First shoe purchase for our tiny human - he's 20 lbs at 8 mo, so we purchased a size 4. These are perfect. Very flexible, warm, look good, and best of all, stay on his feet all day (which means they must be comfortable, right?). I suspect they might run a little large, but that's fine because babies grow fast and there is room for some thicker socks when it gets cold. We will definitely purchase the next size up!**Update 3/22/18**These shoes are just flippin' fabulous. Tiny human is now 13 mo anSee full review