The calculated distance (air line) between Amarpur and Chhāgalnāiya is approximately 36 miles respectively 58 kilometers.
By car or train, the actual journey to Chhāgalnāiya is certainly longer, as only the direct route (as the crow flies) between Amarpur and Chhāgalnāiya has been calculated here.
Air line (approximately)
58 kilometers
31 nautical miles