The calculated distance (air line) between Mantova and Reggio nell'Emilia is approximately 33 miles respectively 53 kilometers.
By car or train, the actual journey to Reggio nell'Emilia is certainly longer, as only the direct route (as the crow flies) between Mantova and Reggio nell'Emilia has been calculated here.
Air line (approximately)
53 kilometers
29 nautical miles