It is sometimes said that the most of the people who have ever lived are alive today. This is obviously not true (see below), but leads to the more interesting question: what fraction of all the people who have ever lived are alive today, and when will this figure reach its maximum?

This is not easy to calculate with any certainty. The raw data looks like this (best guesses, see http://www.prb.org/):

  • Number of humans who have ever lived: 106.5 billion
  • Number alive today (2008): 6.7 billion
  • Births per year: 139 million
  • Deaths per year: 57 million

Current percentage=6.7/106.5=6.29%

This percentage is currently rising, and will do so for the foreseeable future. It should reach 7% in 2019. It will not begin to drop until the net birth rate is far lower than it is now. It never has been and never will be anywhere near 50%.