The calculated distance (air line) between Zürich (Kreis 1) and Sankt Gallen is approximately 39 miles respectively 63 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 1) and Sankt Gallen has been calculated here.
Air line (approximately)
63 kilometers
34 nautical miles