The calculated distance (air line) between Nāḩiyat al Fuhūd and Al Ḩayy is approximately 92 miles respectively 149 kilometers.
By car or train, the actual journey to Al Ḩayy is certainly longer, as only the direct route (as the crow flies) between Nāḩiyat al Fuhūd and Al Ḩayy has been calculated here.
Air line (approximately)
149 kilometers
80 nautical miles