The calculated distance (air line) between Khagrachhari and Chhāgalnāiya is approximately 30 miles respectively 48 kilometers.
By car or train, the actual journey to Chhāgalnāiya is certainly longer, as only the direct route (as the crow flies) between Khagrachhari and Chhāgalnāiya has been calculated here.
Air line (approximately)
48 kilometers
26 nautical miles