There has been much controversy regarding the mathematical sophistication required to construct the Stone Rings of the Megalithic culture. The authors maintain that only the most elementary knowledge (the so-called 'rope and pegs' method) was required by the builders, even in the special non-elliptical sites. The article gives a simple objective algorithm for obtaining ellipse and circle fits to the coordinates of any given site, which may then be used in a statistical study of the metrology of the sites in general. -- AATA