Seattle is about 2.6 times bigger than The Hague (Den Haag).

The Hague (Den Haag) (excluding the city's 15.68 sq km of water area) is approximately 82 sq km, while Seattle is approximately 217 sq km, making Seattle 164% larger than The Hague (Den Haag).
Tip: This to-scale comparison of The Hague (Den Haag) vs. Seattle uses the Mercator projection, which distorts the size of regions near the poles.