The calculated distance (air line) between Sankt Georgen im Schwarzwald and Karlsruhe is approximately 61 miles respectively 98 kilometers.
By car or train, the actual journey to Karlsruhe is certainly longer, as only the direct route (as the crow flies) between Sankt Georgen im Schwarzwald and Karlsruhe has been calculated here.
Air line (approximately)
98 kilometers
53 nautical miles