I am an average size woman, dress size 6-8 (5'6" and 130#) and these fit me with no trouble at all and some room to spare.  They would easily fit someone larger too (but probably not a large muscular male---he might be able to wear the kneepads as elbow pads though!).  They have stretch velco straps so the size is adjustable.  The velcro straps are comfortable, not so tight that they cut off circulation. I like them a LOT better than my old ones, which were not straps but stretchy elastic and hard to get on and off, especially if one was sweating!  These are simple, fast and easy to put on and take off.  These seem well-made;  I've had them for about a month (with usage 3 times a week, for biking) and I expect them to last a long while----but even if they didn't, at this price it's affordable to replace them.  They probebly would work equally well for skating.  They don't hamper one's movement---when wearing them, I pretty much forget that they're there.  For the price, these can't be beat!  I'm very pleased with the purchase.