The calculated distance (air line) between Dobrna and Zagorje ob Savi is approximately 18 miles respectively 29 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 Dobrna and Zagorje ob Savi has been calculated here.
Air line (approximately)
29 kilometers
16 nautical miles