The calculated distance (air line) between Mattighofen and Klagenfurt am Wörthersee is approximately 116 miles respectively 186 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 Mattighofen and Klagenfurt am Wörthersee has been calculated here.
Air line (approximately)
186 kilometers
101 nautical miles