The calculated distance (air line) between Nāḩiyat al Fuhūd and Ad Dasmah is approximately 135 miles respectively 217 kilometers.
By car or train, the actual journey to Ad Dasmah is certainly longer, as only the direct route (as the crow flies) between Nāḩiyat al Fuhūd and Ad Dasmah has been calculated here.
Air line (approximately)
217 kilometers
117 nautical miles