The calculated distance (air line) between Horishni Plavni and Mykolayiv is approximately 159 miles respectively 257 kilometers.
By car or train, the actual journey to Mykolayiv is certainly longer, as only the direct route (as the crow flies) between Horishni Plavni and Mykolayiv has been calculated here.
Air line (approximately)
257 kilometers
138 nautical miles