The calculated distance (air line) between Nieder-Ingelheim and Bad Kreuznach is approximately 13 miles respectively 21 kilometers.
By car or train, the actual journey to Bad Kreuznach is certainly longer, as only the direct route (as the crow flies) between Nieder-Ingelheim and Bad Kreuznach has been calculated here.
Air line (approximately)
21 kilometers
11 nautical miles