The calculated distance (air line) between As Saffānīyah and Al Mubarraz is approximately 185 miles respectively 298 kilometers.
By car or train, the actual journey to Al Mubarraz is certainly longer, as only the direct route (as the crow flies) between As Saffānīyah and Al Mubarraz has been calculated here.
Air line (approximately)
298 kilometers
161 nautical miles