The calculated distance (air line) between Breisach am Rhein and Karlsruhe is approximately 77 miles respectively 124 kilometers.
By car or train, the actual journey to Karlsruhe is certainly longer, as only the direct route (as the crow flies) between Breisach am Rhein and Karlsruhe has been calculated here.
Air line (approximately)
124 kilometers
67 nautical miles