I really wanted to like these, especially at this price.  They came and felt very tight, but I knew they would stretch some.  Well, they really have.  I ordered a M (I am a 7.5 size) and in a few weeks, they are not probably at an 8.  Also, my foot shifts in them so that it hangs over the edge and I often trip ... I bought them because I wear flip flops all yearlong in the house and I wanted some warmth and also some safety because of the sole.  I got the warmth, but the safety is not there - I slip in them all the time!