The calculated distance (air line) between Chefchaouen and Oued Zem is approximately 176 miles respectively 283 kilometers.
By car or train, the actual journey to Oued Zem is certainly longer, as only the direct route (as the crow flies) between Chefchaouen and Oued Zem has been calculated here.
Air line (approximately)
283 kilometers
153 nautical miles