The calculated distance (air line) between Zürich (Kreis 3) and Winterthur is approximately 15 miles respectively 23 kilometers.
By car or train, the actual journey to Winterthur is certainly longer, as only the direct route (as the crow flies) between Zürich (Kreis 3) and Winterthur has been calculated here.
Air line (approximately)
23 kilometers
13 nautical miles