Lake Michigan is about 4.2 times smaller than Great Lakes.

Great Lakes is approximately 243,839 km² (94,147 sq mi), while Lake Michigan is approximately 57,750 km² (22,297 sq mi), making Lake Michigan 23.68% the size of Great Lakes.
Tip: This to-scale comparison of Great Lakes vs. Lake Michigan uses the Mercator projection, which distorts the size of regions near the poles.
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