The calculated distance (air line) between Sarnen and Zürich (Kreis 9) is approximately 35 miles respectively 57 kilometers.
By car or train, the actual journey to Zürich (Kreis 9) is certainly longer, as only the direct route (as the crow flies) between Sarnen and Zürich (Kreis 9) has been calculated here.
Air line (approximately)
57 kilometers
31 nautical miles