New Jersey is about 1.9 times smaller than Guinea-Bissau.

Guinea-Bissau is approximately 36,125 sq km, while New Jersey is approximately 19,211 sq km, making New Jersey 53.18% the size of Guinea-Bissau. Meanwhile, the population of Guinea-Bissau is ~2.0 million people (6.8 million more people live in New Jersey).
Tip: This to-scale comparison of Guinea-Bissau vs. New Jersey uses the Mercator projection, which distorts the size of regions near the poles.