The calculated distance (air line) between La Roca del Vallès and L'Hospitalet de Llobregat is approximately 20 miles respectively 32 kilometers.
By car or train, the actual journey to L'Hospitalet de Llobregat is certainly longer, as only the direct route (as the crow flies) between La Roca del Vallès and L'Hospitalet de Llobregat has been calculated here.
Air line (approximately)
32 kilometers
17 nautical miles