The calculated distance (air line) between Yuen Long Kau Hui and Hang Hau is approximately 18 miles respectively 28 kilometers.
By car or train, the actual journey to Hang Hau is certainly longer, as only the direct route (as the crow flies) between Yuen Long Kau Hui and Hang Hau has been calculated here.
Air line (approximately)
28 kilometers
15 nautical miles