The calculated distance (air line) between 's-Hertogenbosch and Alphen aan den Rijn is approximately 41 miles respectively 65 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 's-Hertogenbosch and Alphen aan den Rijn has been calculated here.
Air line (approximately)
65 kilometers
35 nautical miles