population in usa 2014
1 The population of the United States is estimated at 322,583,006 as of July 1 2014. 2  United States' population is equivalent to 4.45% of the total world population. 3  The U.S. ranks number 3 in the list of countries by population. 4  The population density in the U.S.A. is 34 people per Km2.