Puerto Rico is about 1.8 times bigger than Delaware.

Delaware is approximately 5,060 sq km, while Puerto Rico is approximately 9,104 sq km, making Puerto Rico 80% larger than Delaware. Meanwhile, the population of Delaware is ~897,934 people (2.2 million more people live in Puerto Rico).
Tip: This to-scale comparison of Delaware vs. Puerto Rico uses the Mercator projection, which distorts the size of regions near the poles.