New York City is about 1.8 times smaller than Saint Petersburg.

Saint Petersburg is approximately 1,439 sq km, while New York City (including all five boroughs: Manhattan, Brooklyn, Queens, The Bronx, and Staten Island) is approximately 781 sq km, making New York City 54.27% the size of Saint Petersburg.
Tip: This to-scale comparison of Saint Petersburg vs. New York 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.