Flathead Lake is about 3.7 times smaller than Lake Okeechobee.

Lake Okeechobee is approximately 1,890 km² (730 sq mi), while Flathead Lake is approximately 510 km² (197 sq mi), making Flathead Lake 26.98% the size of Lake Okeechobee.
Tip: This to-scale comparison of Lake Okeechobee vs. Flathead Lake uses the Mercator projection, which distorts the size of regions near the poles.
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