The calculated distance (air line) between Locarno and Zürich (Kreis 3) is approximately 83 miles respectively 134 kilometers.
By car or train, the actual journey to Zürich (Kreis 3) is certainly longer, as only the direct route (as the crow flies) between Locarno and Zürich (Kreis 3) has been calculated here.
Air line (approximately)
134 kilometers
72 nautical miles