The calculated distance (air line) between Winterthur and Zürich (Kreis 9) / Altstetten is approximately 14 miles respectively 22 kilometers.
By car or train, the actual journey to Zürich (Kreis 9) / Altstetten is certainly longer, as only the direct route (as the crow flies) between Winterthur and Zürich (Kreis 9) / Altstetten has been calculated here.
Air line (approximately)
22 kilometers
12 nautical miles