Convert from parasang to gigaparsec

Unit Definition (parasang)
The parasang (Persian - farsang) is an ancient Persian unit of itinerant distance corresponding to approximately 3.5 miles (5.6 kilometers)., or the distance that can be traversed on foot in an hour.

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.