The calculated distance (air line) between Dok Kham Tai and Chiang Rai is approximately 53 miles respectively 85 kilometers.
By car or train, the actual journey to Chiang Rai is certainly longer, as only the direct route (as the crow flies) between Dok Kham Tai and Chiang Rai has been calculated here.
Air line (approximately)
85 kilometers
46 nautical miles