The calculated distance (air line) between Rostov-na-Donu and Taganrog is approximately 38 miles respectively 62 kilometers.
By car or train, the actual journey to Taganrog is certainly longer, as only the direct route (as the crow flies) between Rostov-na-Donu and Taganrog has been calculated here.
Air line (approximately)
62 kilometers
33 nautical miles