The calculated distance (air line) between Trzemeszno and Bydgoszcz is approximately 40 miles respectively 64 kilometers.
By car or train, the actual journey to Bydgoszcz is certainly longer, as only the direct route (as the crow flies) between Trzemeszno and Bydgoszcz has been calculated here.
Air line (approximately)
64 kilometers
34 nautical miles