Mexico City is about 11 times smaller than Beijing.

Beijing is approximately 16,411 sq km, while Mexico City is approximately 1,485 sq km, making Mexico City 9.05% the size of Beijing.
Tip: This to-scale comparison of Beijing vs. Mexico City 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.