The calculated distance (air line) between Heppenheim an der Bergstrasse and Karlsruhe is approximately 45 miles respectively 72 kilometers.
By car or train, the actual journey to Karlsruhe is certainly longer, as only the direct route (as the crow flies) between Heppenheim an der Bergstrasse and Karlsruhe has been calculated here.
Air line (approximately)
72 kilometers
39 nautical miles