The calculated distance (air line) between San Agustín del Guadalix and Zaragoza is approximately 158 miles respectively 254 kilometers.
By car or train, the actual journey to Zaragoza is certainly longer, as only the direct route (as the crow flies) between San Agustín del Guadalix and Zaragoza has been calculated here.
Air line (approximately)
254 kilometers
137 nautical miles