The calculated distance (air line) between Höchstädt an der Donau and Karlsruhe is approximately 102 miles respectively 165 kilometers.
By car or train, the actual journey to Karlsruhe is certainly longer, as only the direct route (as the crow flies) between Höchstädt an der Donau and Karlsruhe has been calculated here.
Air line (approximately)
165 kilometers
89 nautical miles