The calculated distance (air line) between Sant Andreu and Sant Boi de Llobregat is approximately 10 miles respectively 16 kilometers.
By car or train, the actual journey to Sant Boi de Llobregat is certainly longer, as only the direct route (as the crow flies) between Sant Andreu and Sant Boi de Llobregat has been calculated here.
Air line (approximately)
16 kilometers
9 nautical miles