Idaho is about 4.4 times smaller than Tanzania.

Tanzania is approximately 947,300 sq km, while Idaho is approximately 214,314 sq km, making Idaho 22.62% the size of Tanzania. Meanwhile, the population of Tanzania is ~63.9 million people (62.3 million fewer people live in Idaho).
Tip: This to-scale comparison of Tanzania vs. Idaho uses the Mercator projection, which distorts the size of regions near the poles.