The calculated distance (air line) between Sępólno Krajeńskie and Gdańsk is approximately 77 miles respectively 124 kilometers.
By car or train, the actual journey to Gdańsk is certainly longer, as only the direct route (as the crow flies) between Sępólno Krajeńskie and Gdańsk has been calculated here.
Air line (approximately)
124 kilometers
67 nautical miles