The calculated distance (air line) between Birkenwerder and Französisch Buchholz is approximately 9 miles respectively 14 kilometers.
By car or train, the actual journey to Französisch Buchholz is certainly longer, as only the direct route (as the crow flies) between Birkenwerder and Französisch Buchholz has been calculated here.
Air line (approximately)
14 kilometers
8 nautical miles