The calculated distance (air line) between Horní Slavkov and Mladá Boleslav is approximately 94 miles respectively 152 kilometers.
By car or train, the actual journey to Mladá Boleslav is certainly longer, as only the direct route (as the crow flies) between Horní Slavkov and Mladá Boleslav has been calculated here.
Air line (approximately)
152 kilometers
82 nautical miles