The calculated distance (air line) between Bad Soden-Salmünster and Karlsruhe is approximately 98 miles respectively 157 kilometers.
By car or train, the actual journey to Karlsruhe is certainly longer, as only the direct route (as the crow flies) between Bad Soden-Salmünster and Karlsruhe has been calculated here.
Air line (approximately)
157 kilometers
85 nautical miles