The calculated distance (air line) between Chadwell Heath and Southend-on-Sea is approximately 25 miles respectively 40 kilometers.
By car or train, the actual journey to Southend-on-Sea is certainly longer, as only the direct route (as the crow flies) between Chadwell Heath and Southend-on-Sea has been calculated here.
Air line (approximately)
40 kilometers
22 nautical miles