Prague is about 1.6 times bigger than Riga.

Riga is approximately 304 sq km, while Prague is approximately 496 sq km, making Prague 63% larger than Riga.
Tip: This to-scale comparison of Riga vs. Prague 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.