The calculated distance (air line) between Esch-sur-Alzette and Diekirch is approximately 27 miles respectively 43 kilometers.
By car or train, the actual journey to Diekirch is certainly longer, as only the direct route (as the crow flies) between Esch-sur-Alzette and Diekirch has been calculated here.
Air line (approximately)
43 kilometers
23 nautical miles