Convert from ridge to mile [Irish]

Unit Definition (ridge)
The ridge is a traditional Welsh unit of distance equal to 3 leaps or 20 feet 3 inches (6.1722 meters).

Unit Definition (mile [Irish])
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.