The calculated distance (air line) between San Giovanni in Marignano and Reggio nell'Emilia is approximately 115 miles respectively 186 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 San Giovanni in Marignano and Reggio nell'Emilia has been calculated here.
Air line (approximately)
186 kilometers
100 nautical miles