The calculated distance (air line) between Salzburg and Klagenfurt am Wörthersee is approximately 100 miles respectively 162 kilometers.
By car or train, the actual journey to Klagenfurt am Wörthersee is certainly longer, as only the direct route (as the crow flies) between Salzburg and Klagenfurt am Wörthersee has been calculated here.
Air line (approximately)
162 kilometers
87 nautical miles