The population of the United States is expected to reach 300 million on Tuesday at 7:46 a.m. EST.
Listen to a sample of population predictions from people on the National Mall in Washington, D.C.
The world population was 3.5 billion in 1967, the year the 200th million American was born. Today, there are 6.5 billion people in the world.
At some point on Tuesday morning, the population of the United States will hit 300 million people. The estimate is based on U.S. Census data: a birth every seven seconds, a death every 13 seconds and a new immigrant arriving every 31 seconds.
But if you didn't know these demographic statistics, calculating the U.S. population isn't so easy. The last major population milestone — 200 million — occured in 1967, and the topic is rarely discussed unless a milestone is about to occur.
On Friday, we interviewed 80 people on the National Mall in Washington, D.C., right near the Smithsonian Institution. They were asked one question: What's the current population of the United States?
The 80 people surveyed come from all over the country and range in age from 4 to 78. Six people were from England, Australia, and Venezuela.
The answers we received for the U.S. population size ranged from 17,000 to 20 billion. Though roughly 1 out of 4 surveyed knew the population was about to hit 300 million, 1 in 8 said that they had absolutely no idea how many people were living here.
Others guessed. One woman questioned whether the 300 million includes both legal citizens and illegal immigrants. (It does.) A woman and her children extrapolated the population using the number of citizens of California as a guide. Some people said that the population was in the low millions, based on where they were from. Others thought billions.