Tehran is about 24 times smaller than Beijing.

Beijing is approximately 16,411 sq km, while Tehran is approximately 686 sq km, making Tehran 4.18% the size of Beijing.
Tip: This to-scale comparison of Beijing vs. Tehran 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.