The calculated distance (air line) between 's-Hertogenbosch and Nieuwegein is approximately 25 miles respectively 40 kilometers.
By car or train, the actual journey to Nieuwegein is certainly longer, as only the direct route (as the crow flies) between 's-Hertogenbosch and Nieuwegein has been calculated here.
Air line (approximately)
40 kilometers
21 nautical miles