The calculated distance (air line) between Rogaška Slatina and Grosuplje is approximately 51 miles respectively 82 kilometers.
By car or train, the actual journey to Grosuplje is certainly longer, as only the direct route (as the crow flies) between Rogaška Slatina and Grosuplje has been calculated here.
Air line (approximately)
82 kilometers
44 nautical miles