The calculated distance (air line) between Sant Feliu de Llobregat and Sant Martí is approximately 8 miles respectively 13 kilometers.
By car or train, the actual journey to Sant Martí is certainly longer, as only the direct route (as the crow flies) between Sant Feliu de Llobregat and Sant Martí has been calculated here.
Air line (approximately)
13 kilometers
7 nautical miles