The calculated distance (air line) between Šmartno pri Litiji and Mengeš is approximately 15 miles respectively 25 kilometers.
By car or train, the actual journey to Mengeš is certainly longer, as only the direct route (as the crow flies) between Šmartno pri Litiji and Mengeš has been calculated here.
Air line (approximately)
25 kilometers
13 nautical miles