The calculated distance (air line) between Uster / Ober-Uster and Sitten is approximately 101 miles respectively 163 kilometers.
By car or train, the actual journey to Sitten is certainly longer, as only the direct route (as the crow flies) between Uster / Ober-Uster and Sitten has been calculated here.
Air line (approximately)
163 kilometers
88 nautical miles