Amsterdam is about 1.4 times smaller than Osaka.

Osaka is approximately 223 sq km, while Amsterdam is approximately 166 sq km, making Amsterdam 74.33% the size of Osaka.
Tip: This to-scale comparison of Osaka 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.