Big Island of Hawaii is about 1.2 times bigger than Yellowstone National Park.

Yellowstone National Park is approximately 8,983 km² (3,469 sq mi), while Big Island of Hawaii is approximately 10,434 km² (4,029 sq mi), making Big Island of Hawaii 16% larger than Yellowstone National Park.
Tip: This to-scale comparison of Yellowstone National Park vs. Big Island of Hawaii uses the Mercator projection, which distorts the size of regions near the poles.

Compare further: Big Island of Hawaii vs. Yellowstone National Park

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