The calculated distance (air line) between Marske-by-the-Sea and Milton Keynes is approximately 177 miles respectively 284 kilometers.
By car or train, the actual journey to Milton Keynes is certainly longer, as only the direct route (as the crow flies) between Marske-by-the-Sea and Milton Keynes has been calculated here.
Air line (approximately)
284 kilometers
153 nautical miles