Ordered these for my 14-year-old.  He's a shoe size 7 (mens) so these are perfect - there's growing room.  He wears these to school with his sneakers when he has PE.  They wash well and last a long time- I bought some of these for him a year or so ago and he still has them.  After a lot of wash and wear, they are just beginning to get stretched at the tops.  But they are still wearable and have enough elastic to stay up (or as up as he wears them, which isn't very "up.")