The calculated distance (air line) between Zürich (Kreis 7) / Hirslanden and Thun is approximately 61 miles respectively 99 kilometers.
By car or train, the actual journey to Thun is certainly longer, as only the direct route (as the crow flies) between Zürich (Kreis 7) / Hirslanden and Thun has been calculated here.
Air line (approximately)
99 kilometers
53 nautical miles