The calculated distance (air line) between Flawil and Zürich (Kreis 12) is approximately 28 miles respectively 46 kilometers.
By car or train, the actual journey to Zürich (Kreis 12) is certainly longer, as only the direct route (as the crow flies) between Flawil and Zürich (Kreis 12) has been calculated here.
Air line (approximately)
46 kilometers
25 nautical miles