The calculated distance (air line) between Polýgyros and Néa Smýrni is approximately 169 miles respectively 271 kilometers.
By car or train, the actual journey to Néa Smýrni is certainly longer, as only the direct route (as the crow flies) between Polýgyros and Néa Smýrni has been calculated here.
Air line (approximately)
271 kilometers
146 nautical miles