The calculated distance (air line) between Küsnacht and Zürich (Kreis 9) is approximately 7 miles respectively 11 kilometers.
By car or train, the actual journey to Zürich (Kreis 9) is certainly longer, as only the direct route (as the crow flies) between Küsnacht and Zürich (Kreis 9) has been calculated here.
Air line (approximately)
11 kilometers
6 nautical miles