The calculated distance (air line) between Zaporizhzhya and Sievierodonetsk is approximately 172 miles respectively 277 kilometers.
By car or train, the actual journey to Sievierodonetsk is certainly longer, as only the direct route (as the crow flies) between Zaporizhzhya and Sievierodonetsk has been calculated here.
Air line (approximately)
277 kilometers
149 nautical miles