Boise is about 3.7 times smaller than Charlotte.

Charlotte (map shows its 157 named neighbourhoods; the area covers the whole city) is approximately 807 sq km, while Boise is approximately 221 sq km, making Boise 27.33% the size of Charlotte.
Tip: This to-scale comparison of Charlotte vs. Boise uses the Mercator projection, which distorts the size of regions near the poles.
Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.