The calculated distance (air line) between Český Krumlov and Mladá Boleslav is approximately 114 miles respectively 183 kilometers.
By car or train, the actual journey to Mladá Boleslav is certainly longer, as only the direct route (as the crow flies) between Český Krumlov and Mladá Boleslav has been calculated here.
Air line (approximately)
183 kilometers
99 nautical miles