Orange County, California is 13 times larger than Olathe, Kansas.
Area: 157 km2 calculated
Olathe is a city in and is the county seat of Johnson County, Kansas, United States. Located in northeastern Kansas, it is also the fourth most populous city in the state, with a population of 125,872 at the 2010 census. Olathe is the fourth-largest city in the Kansas City metropolitan area. Wikipedia
Area: 2,064 km2 calculated
Orange County is a county in the U.S. state of California. As of the 2010 census, the population was 3,010,232 making it the third-most populous county in California, the sixth-most populous in the United States, and it more populous than twenty-one U.S. states. Its county seat is Santa Ana. Wikipedia