The calculated distance (air line) between Stamboliyski and Veliko Tŭrnovo is approximately 86 miles respectively 138 kilometers.
By car or train, the actual journey to Veliko Tŭrnovo is certainly longer, as only the direct route (as the crow flies) between Stamboliyski and Veliko Tŭrnovo has been calculated here.
Air line (approximately)
138 kilometers
75 nautical miles