Hayward is about 1.4 times smaller than Amsterdam.

Amsterdam is approximately 166 sq km, while Hayward (map shows its 16 named neighbourhoods; the area covers the whole city) is approximately 119 sq km, making Hayward 71.59% the size of Amsterdam.
Tip: This to-scale comparison of Amsterdam vs. Hayward uses the Mercator projection, which distorts the size of regions near the poles.
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