The calculated distance (air line) between Néa Chalkidóna and Chalkída is approximately 31 miles respectively 50 kilometers.
By car or train, the actual journey to Chalkída is certainly longer, as only the direct route (as the crow flies) between Néa Chalkidóna and Chalkída has been calculated here.
Air line (approximately)
50 kilometers
27 nautical miles