The calculated distance (air line) between Konstantinovsk and Rostov-na-Donu is approximately 68 miles respectively 110 kilometers.
By car or train, the actual journey to Rostov-na-Donu is certainly longer, as only the direct route (as the crow flies) between Konstantinovsk and Rostov-na-Donu has been calculated here.
Air line (approximately)
110 kilometers
59 nautical miles