Houston is about 1.5 times smaller than Moscow.

Moscow (map shows its 125 districts within the pre-2012 boundary; the area includes New Moscow) is approximately 2,562 sq km, while Houston is approximately 1,659 sq km, making Houston 64.76% the size of Moscow.
Tip: This to-scale comparison of Moscow vs. Houston 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.