The calculated distance (air line) between Brezová pod Bradlom and Trnava is approximately 20 miles respectively 32 kilometers.
By car or train, the actual journey to Trnava is certainly longer, as only the direct route (as the crow flies) between Brezová pod Bradlom and Trnava has been calculated here.
Air line (approximately)
32 kilometers
17 nautical miles