Holy See (Vatican City) is about 936 times smaller than Heard Island and McDonald Islands.

Heard Island and McDonald Islands is approximately 412 sq km, while Holy See (Vatican City) is approximately 0 sq km, making Holy See (Vatican City) 0.11% the size of Heard Island and McDonald Islands.
Tip: This to-scale comparison of Heard Island and McDonald Islands vs. Holy See (Vatican City) uses the Mercator projection, which distorts the size of regions near the poles.

Compare further: Holy See (Vatican City) vs. Heard Island and McDonald Islands

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