The calculated distance (air line) between Bilhorod-Dnistrovskyi and Odesa is approximately 28 miles respectively 44 kilometers.
By car or train, the actual journey to Odesa is certainly longer, as only the direct route (as the crow flies) between Bilhorod-Dnistrovskyi and Odesa has been calculated here.
Air line (approximately)
44 kilometers
24 nautical miles