The calculated distance (air line) between Neuhaus am Rennweg and Karlsruhe is approximately 160 miles respectively 258 kilometers.
By car or train, the actual journey to Karlsruhe is certainly longer, as only the direct route (as the crow flies) between Neuhaus am Rennweg and Karlsruhe has been calculated here.
Air line (approximately)
258 kilometers
139 nautical miles