Cook Islands is about 81 times smaller than New Jersey.

New Jersey is approximately 19,211 sq km, while Cook Islands is approximately 236 sq km, making Cook Islands 1.23% the size of New Jersey. Meanwhile, the population of New Jersey is ~8.8 million people (8.8 million fewer people live in Cook Islands).
Tip: This to-scale comparison of New Jersey vs. Cook Islands uses the Mercator projection, which distorts the size of regions near the poles.