Convert from button measure to gigaparsec

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 (gigaparsec)
The Gigaparsec is a non-metric unit of distance equal to one billion parsecs, 3.2616 billion light years, or 30.856 78 zettameters (30.856 78 x 1021 kilometers). The unit is used in astronomy.