The calculated distance (air line) between Burg auf Fehmarn and Lütjenburg is approximately 26 miles respectively 43 kilometers.
By car or train, the actual journey to Lütjenburg is certainly longer, as only the direct route (as the crow flies) between Burg auf Fehmarn and Lütjenburg has been calculated here.
Air line (approximately)
43 kilometers
23 nautical miles