The calculated distance (air line) between Lenart v Slov. Goricah and Kočevje is approximately 79 miles respectively 128 kilometers.
By car or train, the actual journey to Kočevje is certainly longer, as only the direct route (as the crow flies) between Lenart v Slov. Goricah and Kočevje has been calculated here.
Air line (approximately)
128 kilometers
69 nautical miles