These run a little small in my opinion. I wear a 9 or 9.5 in Brooks running shoes and bought a 8.5 in these.  I LOVE the support in these shoes. they feel like a tennis shoe, not hard and clumpy like a clog, but you can slip them on like a clog. they are not waterproof, but you can wipe them off easily and at least they aren't mesh so stuff isn't leaking thru.  I actually bought them at a local store, and the price is similar to amazon.  would definitely purchase again!