The calculated distance (air line) between Kecskemét and Budapest XXI. kerület is approximately 46 miles respectively 75 kilometers.
By car or train, the actual journey to Budapest XXI. kerület is certainly longer, as only the direct route (as the crow flies) between Kecskemét and Budapest XXI. kerület has been calculated here.
Air line (approximately)
75 kilometers
40 nautical miles