The calculated distance (air line) between Buchholz in der Nordheide and Barmbek-Nord is approximately 21 miles respectively 33 kilometers.
By car or train, the actual journey to Barmbek-Nord is certainly longer, as only the direct route (as the crow flies) between Buchholz in der Nordheide and Barmbek-Nord has been calculated here.
Air line (approximately)
33 kilometers
18 nautical miles