U.S. POPClock Projection

According to the U.S. Census Bureau, the resident population of the United States, projected to 11/23/12 at 16:41 UTC (EST+5) is

314,818,416

COMPONENT SETTINGS FOR NOVEMBER 2012
One birth every	8 seconds
One death every	13 seconds
One international migrant (net) every	44 seconds
Net gain of one person every	15 seconds

The U.S. population clock shows a series of short-term projections for the resident population of the United States. This includes people whose usual residence is in the 50 states and the District of Columbia. These projections do not include members of the Armed Forces overseas, their dependents, or other U.S. citizens residing outside the United States.

The projections are based on a monthly series of population estimates starting with the April 1, 2010 resident population from the 2010 Census. To produce the monthly postcensal national resident population estimates, the April 1 population count is updated by adding births, subtracting deaths, and adding net international migration since the census date.

At the end of each year, a new series of population estimates, from the census date forward, is used to revise the postcensal estimates, including the population clock projections series. Once a series of monthly projections is completed, the daily population clock numbers are derived by interpolation. Within each calendar month, the daily numerical population change is assumed to be constant, subject to negligible differences caused by rounding.

Population estimates produced by the U.S. Census Bureau for the United States, states, counties, and cities or towns can be found on the Population Estimates web page. Long-term projections for the United States and states can be found on the Population Projections web page.

Source

http://www.census.gov/population/www/popclockus.html