Austin is about 2.9 times bigger than Jackson.

Jackson (map shows its 125 named neighbourhoods; the area covers the whole city) is approximately 289 sq km, while Austin (map shows its 70 named neighbourhoods; the area covers the whole city) is approximately 829 sq km, making Austin 186% larger than Jackson.
Tip: This to-scale comparison of Jackson vs. Austin 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.