The calculated distance (air line) between Ad Dasmah and As Saffānīyah is approximately 106 miles respectively 171 kilometers.
By car or train, the actual journey to As Saffānīyah is certainly longer, as only the direct route (as the crow flies) between Ad Dasmah and As Saffānīyah has been calculated here.
Air line (approximately)
171 kilometers
92 nautical miles