The calculated distance (air line) between Thalwil and Zürich (Kreis 9) is approximately 7 miles respectively 12 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 Thalwil and Zürich (Kreis 9) has been calculated here.
Air line (approximately)
12 kilometers
6 nautical miles