Illinois is about 349 times bigger than Heard Island and McDonald Islands.

Heard Island and McDonald Islands is approximately 412 sq km, while Illinois is approximately 143,961 sq km, making Illinois 34,842% larger than Heard Island and McDonald Islands.
Tip: This to-scale comparison of Heard Island and McDonald Islands vs. Illinois uses the Mercator projection, which distorts the size of regions near the poles.

Compare further: Illinois vs. Heard Island and McDonald Islands

Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.