The calculated distance (air line) between Chiang Klang and Chiang Rai is approximately 79 miles respectively 128 kilometers.
By car or train, the actual journey to Chiang Rai is certainly longer, as only the direct route (as the crow flies) between Chiang Klang and Chiang Rai has been calculated here.
Air line (approximately)
128 kilometers
69 nautical miles