United States is approximately 9,833,517 sq km, while Papua New Guinea is approximately 462,840 sq km, making Papua New Guinea 4.71% the size of United States. Meanwhile, the population of United States is ~332.6 million people (325.4 million fewer people live in Papua New Guinea).
This to-scale map shows a size comparison of United States compared to Papua New Guinea. For more details, see an in-depth quality of life comparison of Papua New Guinea vs. United States using our country comparison tool.