The calculated distance (air line) between Acilia-Castel Fusano-Ostia Antica and Montecompatri is approximately 21 miles respectively 34 kilometers.
By car or train, the actual journey to Montecompatri is certainly longer, as only the direct route (as the crow flies) between Acilia-Castel Fusano-Ostia Antica and Montecompatri has been calculated here.
Air line (approximately)
34 kilometers
18 nautical miles