Orange County, California is 3 times larger than Singapore.
Area: 697 km2 World Factbook
Population: 5,567,301 (July 2014) World Factbook
Singapore, officially the Republic of Singapore, is a sovereign city-state and island country in Southeast Asia. It lies off the southern tip of the Malay Peninsula and is 137 kilometres north of the equator. 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