"Medium" is typically a size 8-10.  I am a size 8, so I thought this would be the right one to order.  After trying them on, I would say they are a full two sizes smaller than what is advertised.  I would add that these are probably a 30 inch inseam for size Medium, which is a bit shorter than I expected.  They are attractive, however, and they washed and ironed well.