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