The calculated distance (air line) between Néa Chalkidóna and Kateríni is approximately 168 miles respectively 271 kilometers.
By car or train, the actual journey to Kateríni is certainly longer, as only the direct route (as the crow flies) between Néa Chalkidóna and Kateríni has been calculated here.
Air line (approximately)
271 kilometers
146 nautical miles