Bilbao to San Sebastián distance

Bilbao to San Sebastián by road

The fastest driving route is 103 km (63.9 mi) long and takes about 1 hr 20 min without stops or traffic. It runs mostly on the AP-8 (75.7 km), the BI-30 (13.7 km), and the GI-20 (5.6 km).

The whole route stays in the Basque Country. That’s an average of 78 km/h (49 mph), and at under two hours you can do it without stopping. The time is OSRM’s estimate with OpenStreetMap data: no traffic and speeds somewhat below the limits, so real trips can differ.

Straight-line distance and bearing

In a straight line, the shortest distance over the Earth’s surface, Bilbao and San Sebastián are 76.4 km (47.5 mi) apart. That’s the geodesic on the WGS84 ellipsoid, the distance “as the crow flies”.

The road is 35% longer: for every 100 km in a straight line you drive 135. That’s a big detour: the fastest route strays quite far from the straight line. Of the 40 Spanish pairs in this series, it ranks 6th for detour (the average is 24%).

From Bilbao, San Sebastián lies to the east (bearing 85°), and from San Sebastián, Bilbao lies to the west.

Halfway between Bilbao and San Sebastián

Halfway along the straight line, 38.2 km (23.7 mi) from each city, is the point 43.2938° N, 2.4548° W. It falls near Berriatua (Biscay, pop. 1,224), 1.9 km away. The nearest town of 20,000 people or more is Eibar (Gipuzkoa, pop. 27,484), 12.2 km away.

By road, the halfway point is 51.5 km (32.0 mi) from each city, near Elgoibar (Gipuzkoa, pop. 11,705), 2.9 km away. The nearest town of 20,000 people or more is Eibar (Gipuzkoa, pop. 27,484), 3.0 km away. The two midpoints are 11.2 km apart: if you want to meet halfway, the one on the road is the useful one.

The two cities

Bilbao and San Sebastián sit at almost the same elevation: 7 m (23 ft) and 8 m (26 ft).

Bilbao has 351,124 people and San Sebastián 189,866 people (INE population register, January 1, 2025).