The calculated distance (air line) between Gillingham and Stoke-on-Trent is approximately 136 miles respectively 219 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 Gillingham and Stoke-on-Trent has been calculated here.
Air line (approximately)
219 kilometers
118 nautical miles