The calculated distance (air line) between Rum and Klagenfurt am Wörthersee is approximately 142 miles respectively 229 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 Rum and Klagenfurt am Wörthersee has been calculated here.
Air line (approximately)
229 kilometers
123 nautical miles