The calculated distance (air line) between Sv. Ana v Slov. Goricah and Krško is approximately 51 miles respectively 81 kilometers.
By car or train, the actual journey to Krško is certainly longer, as only the direct route (as the crow flies) between Sv. Ana v Slov. Goricah and Krško has been calculated here.
Air line (approximately)
81 kilometers
44 nautical miles