The calculated distance (air line) between Manshīyat al Qanāţir and New Cairo is approximately 24 miles respectively 39 kilometers.
By car or train, the actual journey to New Cairo is certainly longer, as only the direct route (as the crow flies) between Manshīyat al Qanāţir and New Cairo has been calculated here.
Air line (approximately)
39 kilometers
21 nautical miles