Wisconsin is about 596 times bigger than Cook Islands.

Cook Islands is approximately 236 sq km, while Wisconsin is approximately 140,663 sq km, making Wisconsin 59,503% larger than Cook Islands. Meanwhile, the population of Cook Islands is ~8,128 people (5.7 million more people live in Wisconsin).
Tip: This to-scale comparison of Cook Islands vs. Wisconsin uses the Mercator projection, which distorts the size of regions near the poles.