Lincoln, Nebraska is 3.4 times larger than Boulder, Colorado.
Area: 68 km2 calculated
Boulder is the county seat and most populous city of Boulder County and the 11th most populous city in the U.S. state of Colorado. Boulder is located at the base of the foothills of the Rocky Mountains at an elevation of 5,430 feet. The city is 25 miles northwest of Denver. Wikipedia
Area: 230 km2 calculated
Lincoln is the capital and the second-most populous city of the State of Nebraska, after Omaha. Lincoln is also the county seat of Lancaster County and the home of the University of Nebraska. Lincoln's population in 2013 was estimated at 268,738. Wikipedia