The calculated distance (air line) between Behbahān and Ar Rumaythīyah is approximately 157 miles respectively 253 kilometers.
By car or train, the actual journey to Ar Rumaythīyah is certainly longer, as only the direct route (as the crow flies) between Behbahān and Ar Rumaythīyah has been calculated here.
Air line (approximately)
253 kilometers
137 nautical miles