The calculated distance (air line) between Al Qāhirah al Jadīdah and Al Fashn is approximately 90 miles respectively 145 kilometers.
By car or train, the actual journey to Al Fashn is certainly longer, as only the direct route (as the crow flies) between Al Qāhirah al Jadīdah and Al Fashn has been calculated here.
Air line (approximately)
145 kilometers
79 nautical miles