The calculated distance (air line) between Korsun-Shevchenkivskyy and Mykolayiv is approximately 172 miles respectively 277 kilometers.
By car or train, the actual journey to Mykolayiv is certainly longer, as only the direct route (as the crow flies) between Korsun-Shevchenkivskyy and Mykolayiv has been calculated here.
Air line (approximately)
277 kilometers
149 nautical miles