The calculated distance (air line) between Rivne and Yuzhnoukrayinsk is approximately 39 miles respectively 63 kilometers.
By car or train, the actual journey to Yuzhnoukrayinsk is certainly longer, as only the direct route (as the crow flies) between Rivne and Yuzhnoukrayinsk has been calculated here.
Air line (approximately)
63 kilometers
34 nautical miles