The calculated distance (air line) between Nieder-Ingelheim and Wiesbaden is approximately 11 miles respectively 17 kilometers.
By car or train, the actual journey to Wiesbaden is certainly longer, as only the direct route (as the crow flies) between Nieder-Ingelheim and Wiesbaden has been calculated here.
Air line (approximately)
17 kilometers
9 nautical miles