Manhattan is about 2.3 times smaller than Nantucket.

Nantucket is approximately 124 km² (48 sq mi), while Manhattan is approximately 55 km² (21 sq mi), making Manhattan 44.05% the size of Nantucket.
Tip: This to-scale comparison of Nantucket vs. Manhattan uses the Mercator projection, which distorts the size of regions near the poles.
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