Great Lakes is about 4.2 times bigger than Lake Michigan.

Lake Michigan is approximately 57,750 km² (22,297 sq mi), while Great Lakes is approximately 243,839 km² (94,147 sq mi), making Great Lakes 322% larger than Lake Michigan.
Tip: This to-scale comparison of Lake Michigan vs. Great Lakes uses the Mercator projection, which distorts the size of regions near the poles.
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