The calculated distance (air line) between Therwil and Zürich (Kreis 9) is approximately 44 miles respectively 71 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 Therwil and Zürich (Kreis 9) has been calculated here.
Air line (approximately)
71 kilometers
38 nautical miles