The calculated distance (air line) between Zürich (Kreis 7) / Fluntern and Uster is approximately 8 miles respectively 13 kilometers.
By car or train, the actual journey to Uster is certainly longer, as only the direct route (as the crow flies) between Zürich (Kreis 7) / Fluntern and Uster has been calculated here.
Air line (approximately)
13 kilometers
7 nautical miles