How many people have ever lived on planet Earth? Quantifying all of humanity requires a firm starting date for when humans became, well, human. Evolution is a gradual process, so figuring out the start date for humankind is no easy task. For the purposes of this exercise, however, demographers use 190,000 BCE as the cutoff.
There are two opposing points to consider when thinking about prehistoric humans:
Around the chosen start date, the global cohort of humans was quite small—perhaps as low as only 30,000 individuals.
Before the modern era, lifespans were much shorter, so long stretches of time can actually influence numbers drastically.
With this context and timeframe in mind, the demographers estimate that 109 billion people have lived and died over the course of 192,000 years. If we add the number of people alive today, we get 117 billion humans that have ever lived.
This means that for every person alive today, there are approximately 14 people who are no longer with us.