The calculated distance (air line) between Hartley and Stoke-on-Trent is approximately 154 miles respectively 247 kilometers.
By car or train, the actual journey to Stoke-on-Trent is certainly longer, as only the direct route (as the crow flies) between Hartley and Stoke-on-Trent has been calculated here.
Air line (approximately)
247 kilometers
133 nautical miles