The calculated distance (air line) between Petřvald and Mladá Boleslav is approximately 160 miles respectively 257 kilometers.
By car or train, the actual journey to Mladá Boleslav is certainly longer, as only the direct route (as the crow flies) between Petřvald and Mladá Boleslav has been calculated here.
Air line (approximately)
257 kilometers
139 nautical miles