The calculated distance (air line) between Mörfelden-Walldorf and Karlsruhe is approximately 69 miles respectively 110 kilometers.
By car or train, the actual journey to Karlsruhe is certainly longer, as only the direct route (as the crow flies) between Mörfelden-Walldorf and Karlsruhe has been calculated here.
Air line (approximately)
110 kilometers
60 nautical miles