The calculated distance (air line) between Yau Yat Tsuen and Yuen Long is approximately 12 miles respectively 20 kilometers.
By car or train, the actual journey to Yuen Long is certainly longer, as only the direct route (as the crow flies) between Yau Yat Tsuen and Yuen Long has been calculated here.
Air line (approximately)
20 kilometers
11 nautical miles