I  read other reviews before ordering these, and because one or two reviews made a negative comment about how thin they were, I only ordered 2 pair to start.  I was actually suprised that they were so thick.  Any thicker and there would be too much bulk for my shoes to fit comfortably.  They were about the same as my Injini socks, which are labeled "thin."  I am a female, wear a size 8 shoe,  and purchased medium.  I found them to be a bit tight around my calves/ankles.  My  Injini socks are softer, have more give, and are seamless around the toes.  But Injini socks cost $12 and these were $4 (($8 for two pair) so I felt  they deserved 5 stars for value.  Their advantage over Injini socks is that there is no left or right sock.  Interchangeable.  I will be buying more.  Wish they had brown.