The calculated distance (air line) between Sant Boi de Llobregat and Castellbisbal is approximately 10 miles respectively 15 kilometers.
By car or train, the actual journey to Castellbisbal is certainly longer, as only the direct route (as the crow flies) between Sant Boi de Llobregat and Castellbisbal has been calculated here.
Air line (approximately)
15 kilometers
8 nautical miles