The calculated distance (air line) between So Kwun Wat Tsuen and Kai Tak is approximately 13 miles respectively 21 kilometers.
By car or train, the actual journey to Kai Tak is certainly longer, as only the direct route (as the crow flies) between So Kwun Wat Tsuen and Kai Tak has been calculated here.
Air line (approximately)
21 kilometers
11 nautical miles