The calculated distance (air line) between Breitenfurt bei Wien and Klagenfurt am Wörthersee is approximately 135 miles respectively 218 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 Breitenfurt bei Wien and Klagenfurt am Wörthersee has been calculated here.
Air line (approximately)
218 kilometers
118 nautical miles