The calculated distance (air line) between Kovin and Sremska Mitrovica is approximately 69 miles respectively 110 kilometers.
By car or train, the actual journey to Sremska Mitrovica is certainly longer, as only the direct route (as the crow flies) between Kovin and Sremska Mitrovica has been calculated here.
Air line (approximately)
110 kilometers
60 nautical miles