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