Convert from button measure to alen [Danish]

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 (alen [Danish])
The Danish Alen (also used in Norway) is slightly longer than the Scandinavian Alen. It is just longer than two feet and more precisely equal to 62.77 centimeters (24.71 inches).