The calculated distance (air line) between Casalmaggiore and Reggio nell'Emilia is approximately 23 miles respectively 36 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 Casalmaggiore and Reggio nell'Emilia has been calculated here.
Air line (approximately)
36 kilometers
20 nautical miles