The calculated distance (air line) between Uster / Ober-Uster and Chur is approximately 51 miles respectively 82 kilometers.
By car or train, the actual journey to Chur is certainly longer, as only the direct route (as the crow flies) between Uster / Ober-Uster and Chur has been calculated here.
Air line (approximately)
82 kilometers
44 nautical miles