Convert from span to mile [Roman, ancient]

Unit Definition (span)
Span is the width of a human hand, from the tip of the thumb to the tip of the pinky finger.

Unit Definition (mile [Roman, ancient])
A non metric unit of length; a statute mile, used for distances over land, is defined as 5280 ft.; a nautical mile, used for distances along the surface of the oceans, is defined as one minute of arc measured along the equator, which equals 6080.27 fit or 1.1516 statute miles.