The calculated distance (air line) between Chilmāri and Nārāyanganj is approximately 144 miles respectively 232 kilometers.
By car or train, the actual journey to Nārāyanganj is certainly longer, as only the direct route (as the crow flies) between Chilmāri and Nārāyanganj has been calculated here.
Air line (approximately)
232 kilometers
125 nautical miles