The calculated distance (air line) between Deutschlandsberg and Klagenfurt am Wörthersee is approximately 45 miles respectively 73 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 Deutschlandsberg and Klagenfurt am Wörthersee has been calculated here.
Air line (approximately)
73 kilometers
39 nautical miles