The calculated distance (air line) between Kalývia Thorikoú and Petroúpolis is approximately 19 miles respectively 31 kilometers.
By car or train, the actual journey to Petroúpolis is certainly longer, as only the direct route (as the crow flies) between Kalývia Thorikoú and Petroúpolis has been calculated here.
Air line (approximately)
31 kilometers
17 nautical miles