Singapore is about 298 times smaller than Idaho.

Idaho is approximately 214,314 sq km, while Singapore is approximately 719 sq km, making Singapore 0.34% the size of Idaho. Meanwhile, the population of Idaho is ~1.6 million people (4.4 million more people live in Singapore).
Tip: This to-scale comparison of Idaho vs. Singapore uses the Mercator projection, which distorts the size of regions near the poles.