The calculated distance (air line) between Jablonec nad Nisou and Mladá Boleslav is approximately 25 miles respectively 40 kilometers.
By car or train, the actual journey to Mladá Boleslav is certainly longer, as only the direct route (as the crow flies) between Jablonec nad Nisou and Mladá Boleslav has been calculated here.
Air line (approximately)
40 kilometers
21 nautical miles