The calculated distance (air line) between San Martino Buon Albergo and Ferrara is approximately 48 miles respectively 77 kilometers.
By car or train, the actual journey to Ferrara is certainly longer, as only the direct route (as the crow flies) between San Martino Buon Albergo and Ferrara has been calculated here.
Air line (approximately)
77 kilometers
41 nautical miles