The calculated distance (air line) between Carabanchel and Alcalá de Henares is approximately 20 miles respectively 32 kilometers.
By car or train, the actual journey to Alcalá de Henares is certainly longer, as only the direct route (as the crow flies) between Carabanchel and Alcalá de Henares has been calculated here.
Air line (approximately)
32 kilometers
18 nautical miles