The calculated distance (air line) between Al Fallūjah and Al Musayyib is approximately 49 miles respectively 79 kilometers.
By car or train, the actual journey to Al Musayyib is certainly longer, as only the direct route (as the crow flies) between Al Fallūjah and Al Musayyib has been calculated here.
Air line (approximately)
79 kilometers
43 nautical miles