The calculated distance (air line) between Zwolle and Alphen aan den Rijn is approximately 66 miles respectively 107 kilometers.
By car or train, the actual journey to Alphen aan den Rijn is certainly longer, as only the direct route (as the crow flies) between Zwolle and Alphen aan den Rijn has been calculated here.
Air line (approximately)
107 kilometers
58 nautical miles