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