The calculated distance (air line) between Néa Chalkidóna and Thessaloníki is approximately 186 miles respectively 299 kilometers.
By car or train, the actual journey to Thessaloníki is certainly longer, as only the direct route (as the crow flies) between Néa Chalkidóna and Thessaloníki has been calculated here.
Air line (approximately)
299 kilometers
161 nautical miles