The calculated distance (air line) between Calderara di Reno and Castel Maggiore is approximately 5 miles respectively 7 kilometers.
By car or train, the actual journey to Castel Maggiore is certainly longer, as only the direct route (as the crow flies) between Calderara di Reno and Castel Maggiore has been calculated here.
Air line (approximately)
7 kilometers
4 nautical miles