The calculated distance (air line) between Agios Ioannis Rentis and Kateríni is approximately 171 miles respectively 275 kilometers.
By car or train, the actual journey to Kateríni is certainly longer, as only the direct route (as the crow flies) between Agios Ioannis Rentis and Kateríni has been calculated here.
Air line (approximately)
275 kilometers
148 nautical miles