The calculated distance (air line) between Knyazhichi and Pereiaslav is approximately 40 miles respectively 65 kilometers.
By car or train, the actual journey to Pereiaslav is certainly longer, as only the direct route (as the crow flies) between Knyazhichi and Pereiaslav has been calculated here.
Air line (approximately)
65 kilometers
35 nautical miles