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