State size comparison
Illinois is about 1.9 times smaller than Colorado.
Colorado is approximately 268,627 sq km, while Illinois is approximately 143,961 sq km, making Illinois 53.59% the size of Colorado. Meanwhile, the population of Colorado is ~5.0 million people (7.8 million more people live in Illinois).
This to-scale comparison of Colorado vs. Illinois uses the Mercator projection, which distorts the size of regions near the poles. Learn more. Note: Try dragging the outline to reposition.