The calculated distance (air line) between Cox’s Bāzār and Serchhīp is approximately 139 miles respectively 223 kilometers.
By car or train, the actual journey to Serchhīp is certainly longer, as only the direct route (as the crow flies) between Cox’s Bāzār and Serchhīp has been calculated here.
Air line (approximately)
223 kilometers
121 nautical miles