The calculated distance (air line) between Dongguan and Tin Shui Wai is approximately 42 miles respectively 68 kilometers.
By car or train, the actual journey to Tin Shui Wai is certainly longer, as only the direct route (as the crow flies) between Dongguan and Tin Shui Wai has been calculated here.
Air line (approximately)
68 kilometers
36 nautical miles