Papua New Guinea is about 3.2 times bigger than Illinois.

Illinois is approximately 143,961 sq km, while Papua New Guinea is approximately 462,840 sq km, making Papua New Guinea 222% larger than Illinois. Meanwhile, the population of Illinois is ~12.8 million people (3.2 million fewer people live in Papua New Guinea).
Tip: This to-scale comparison of Illinois vs. Papua New Guinea uses the Mercator projection, which distorts the size of regions near the poles.