The calculated distance (air line) between Tápiószentmárton and Kecskemét is approximately 30 miles respectively 48 kilometers.
By car or train, the actual journey to Kecskemét is certainly longer, as only the direct route (as the crow flies) between Tápiószentmárton and Kecskemét has been calculated here.
Air line (approximately)
48 kilometers
26 nautical miles