I bought these for my 2 month old son, he's 12lbs and has average size baby feet!  They are slightly big on him but they still stay on just the same!  Other socks do NOT stay on his feet!  Very cute and I get compliments on them all the time.  They come in a tiny shoe box, ready for gift giving if need be.  I hope to get at least 3 more months of use out of them before he outgrows them.  Not sure a 12 month old would still fit in these, especially after they are washed, they shrink a little...