The calculated distance (air line) between Horta-Guinardó and Viladecans is approximately 11 miles respectively 17 kilometers.
By car or train, the actual journey to Viladecans is certainly longer, as only the direct route (as the crow flies) between Horta-Guinardó and Viladecans has been calculated here.
Air line (approximately)
17 kilometers
9 nautical miles