The calculated distance (air line) between Mengeš and Zagorje ob Savi is approximately 20 miles respectively 33 kilometers.
By car or train, the actual journey to Zagorje ob Savi is certainly longer, as only the direct route (as the crow flies) between Mengeš and Zagorje ob Savi has been calculated here.
Air line (approximately)
33 kilometers
18 nautical miles