Antwerp is about 1.3 times bigger than Amsterdam.

Amsterdam is approximately 166 sq km, while Antwerp (map shows its 62 named neighbourhoods; the area covers the whole city) is approximately 208 sq km, making Antwerp 26% larger than Amsterdam.
Tip: This to-scale comparison of Amsterdam vs. Antwerp 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.