The calculated distance (air line) between Zürich (Kreis 2) / Wollishofen and Sankt Gallen is approximately 40 miles respectively 64 kilometers.
By car or train, the actual journey to Sankt Gallen is certainly longer, as only the direct route (as the crow flies) between Zürich (Kreis 2) / Wollishofen and Sankt Gallen has been calculated here.
Air line (approximately)
64 kilometers
35 nautical miles