Los Angeles is about 13 times bigger than Missoula.

Missoula (map shows its 17 named neighbourhoods; the area covers the whole city) is approximately 91 sq km, while Los Angeles (including the city proper only) is approximately 1,215 sq km, making Los Angeles 1,239% larger than Missoula.
Tip: This to-scale comparison of Missoula vs. Los Angeles 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.