Idaho is around the same size as Guyana.

Guyana is approximately 214,969 sq km, while Idaho is approximately 214,314 sq km, making Idaho 99.7% the size of Guyana. Meanwhile, the population of Guyana is ~789,683 people (777,899 more people live in Idaho).
Tip: This to-scale comparison of Guyana vs. Idaho uses the Mercator projection, which distorts the size of regions near the poles.