The calculated distance (air line) between Spiez and Zürich (Kreis 10) is approximately 63 miles respectively 101 kilometers.
By car or train, the actual journey to Zürich (Kreis 10) is certainly longer, as only the direct route (as the crow flies) between Spiez and Zürich (Kreis 10) has been calculated here.
Air line (approximately)
101 kilometers
55 nautical miles