State size comparison
Illinois is about 1.2 times smaller than Washington.
Washington is approximately 172,348 sq km, while Illinois is approximately 143,961 sq km, making Illinois 83.53% the size of Washington. Meanwhile, the population of Washington is ~6.7 million people (6.1 million more people live in Illinois).
This to-scale comparison of Washington vs. Illinois uses the Mercator projection, which distorts the size of regions near the poles. Learn more. Note: Try dragging the outline to reposition.