Seattle is about 3.3 times smaller than Singapore.

Singapore is approximately 719 sq km, while Seattle is approximately 217 sq km, making Seattle 30.21% the size of Singapore.
Tip: This to-scale comparison of Singapore vs. Seattle uses the Mercator projection, which distorts the size of regions near the poles.
Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.