The calculated distance (air line) between Spiez and Zürich (Kreis 11) is approximately 64 miles respectively 103 kilometers.
By car or train, the actual journey to Zürich (Kreis 11) is certainly longer, as only the direct route (as the crow flies) between Spiez and Zürich (Kreis 11) has been calculated here.
Air line (approximately)
103 kilometers
56 nautical miles