The calculated distance (air line) between Zürich (Kreis 9) / Altstetten and Sitten is approximately 96 miles respectively 155 kilometers.
By car or train, the actual journey to Sitten is certainly longer, as only the direct route (as the crow flies) between Zürich (Kreis 9) / Altstetten and Sitten has been calculated here.
Air line (approximately)
155 kilometers
84 nautical miles