The calculated distance (air line) between Neustadt (Hessen) and Karlsruhe is approximately 131 miles respectively 211 kilometers.
By car or train, the actual journey to Karlsruhe is certainly longer, as only the direct route (as the crow flies) between Neustadt (Hessen) and Karlsruhe has been calculated here.
Air line (approximately)
211 kilometers
114 nautical miles