The calculated distance (air line) between Ermoúpolis and Agios Dimitrios is approximately 74 miles respectively 120 kilometers.
By car or train, the actual journey to Agios Dimitrios is certainly longer, as only the direct route (as the crow flies) between Ermoúpolis and Agios Dimitrios has been calculated here.
Air line (approximately)
120 kilometers
64 nautical miles