Really cute socks but the size is big.  I recommend buy a size smaller.  I bought the SX size for my 2 1/2 year old grandson who wears a size 8 shoe.  According to the sizing info these should have fit him very well but they are so big the sock toes turn under when putting his shoes on. The good thing is that he will grow into them probably by fall/winter.  Really like these construction socks and wish they came in some more colors as he is crazy about construction trucks.