The calculated distance (air line) between Karbala and An Nu‘mānīyah is approximately 81 miles respectively 130 kilometers.
By car or train, the actual journey to An Nu‘mānīyah is certainly longer, as only the direct route (as the crow flies) between Karbala and An Nu‘mānīyah has been calculated here.
Air line (approximately)
130 kilometers
70 nautical miles