Atlanta is about 2.5 times bigger than Kaiserslautern.

Kaiserslautern is approximately 140 sq km, while Atlanta (map shows its 114 named neighbourhoods; the area covers the whole city) is approximately 350 sq km, making Atlanta 151% larger than Kaiserslautern.
Tip: This to-scale comparison of Kaiserslautern vs. Atlanta 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.