Convert from button measure to milla [Spanish]

Unit Definition (button measure)
The button measure is a unit of distance equal to 1/40 inch (0.635 millimeter), used to measure the thickness of buttons.

Unit Definition (milla [Spanish])
The milla is a traditional Spanish mile, equal to 5000 pies (Spanish feet) or 8 estadios. This is about 1392 meters, 4567 feet, or 0.865 statute mile.