The calculated distance (air line) between Stockport and Ashton-under-Lyne is approximately 6 miles respectively 10 kilometers.
By car or train, the actual journey to Ashton-under-Lyne is certainly longer, as only the direct route (as the crow flies) between Stockport and Ashton-under-Lyne has been calculated here.
Air line (approximately)
10 kilometers
5 nautical miles