The calculated distance (air line) between San Tin and Tai Kok Tsui is approximately 14 miles respectively 22 kilometers.
By car or train, the actual journey to Tai Kok Tsui is certainly longer, as only the direct route (as the crow flies) between San Tin and Tai Kok Tsui has been calculated here.
Air line (approximately)
22 kilometers
12 nautical miles