The calculated distance (air line) between Rubí and El Prat de Llobregat is approximately 12 miles respectively 19 kilometers.
By car or train, the actual journey to El Prat de Llobregat is certainly longer, as only the direct route (as the crow flies) between Rubí and El Prat de Llobregat has been calculated here.
Air line (approximately)
19 kilometers
10 nautical miles