The calculated distance (air line) between Korsun-Shevchenkivskyy and Kyiv is approximately 79 miles respectively 126 kilometers.
By car or train, the actual journey to Kyiv is certainly longer, as only the direct route (as the crow flies) between Korsun-Shevchenkivskyy and Kyiv has been calculated here.
Air line (approximately)
126 kilometers
68 nautical miles