Pittsburgh is about 3.6 times smaller than Warsaw.

Warsaw is approximately 517 sq km, while Pittsburgh is approximately 143 sq km, making Pittsburgh 27.73% the size of Warsaw.
Tip: This to-scale comparison of Warsaw vs. Pittsburgh 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.