The calculated distance (air line) between Mataró and Arenys de Munt is approximately 7 miles respectively 11 kilometers.
By car or train, the actual journey to Arenys de Munt is certainly longer, as only the direct route (as the crow flies) between Mataró and Arenys de Munt has been calculated here.
Air line (approximately)
11 kilometers
6 nautical miles