The calculated distance (air line) between Néa Kallikráteia and Acharnés is approximately 158 miles respectively 255 kilometers.
By car or train, the actual journey to Acharnés is certainly longer, as only the direct route (as the crow flies) between Néa Kallikráteia and Acharnés has been calculated here.
Air line (approximately)
255 kilometers
137 nautical miles