Amsterdam is about 1.3 times smaller than Boise.

Boise is approximately 221 sq km, while Amsterdam is approximately 166 sq km, making Amsterdam 75.16% the size of Boise.
Tip: This to-scale comparison of Boise vs. Amsterdam 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.