The calculated distance (air line) between Tolosa and Donostia / San Sebastián is approximately 13 miles respectively 21 kilometers.
By car or train, the actual journey to Donostia / San Sebastián is certainly longer, as only the direct route (as the crow flies) between Tolosa and Donostia / San Sebastián has been calculated here.
Air line (approximately)
21 kilometers
12 nautical miles