Atlanta is about 1.6 times smaller than Columbus.

Columbus is approximately 574 sq km, while Atlanta (map shows its 114 named neighbourhoods; the area covers the whole city) is approximately 350 sq km, making Atlanta 61.08% the size of Columbus.
Tip: This to-scale comparison of Columbus 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.