The calculated distance (air line) between Al Mishkhāb and Nāḩiyat al Fuhūd is approximately 144 miles respectively 231 kilometers.
By car or train, the actual journey to Nāḩiyat al Fuhūd is certainly longer, as only the direct route (as the crow flies) between Al Mishkhāb and Nāḩiyat al Fuhūd has been calculated here.
Air line (approximately)
231 kilometers
125 nautical miles