It could possibly be that 6.5 percent of all humans ever born are still alive today, according to a semi-scientific approach to calculating the number of births of humans - ever!

Because many people so often ask the question “how many people have lived on earth, ever?” scientists have endeavored, just as a fun exercise, to come up with a bit of a guesstimate.

It can’t even be called an estimate, because there are so many factors involved. And with so much information that is not available to us anymore, even the information used for calculating this is often just a guess.

The semi-scientific approach was to guesstimate the number of people ever born and population sizes at different stages in history from antiquity to the present.Assumed birth rates based on knowledge of the time periods were then applied.

This approach led to an answer of about 108 billion births since the dawn of the human race. It is conceded that this method underestimates the number of births to some degree.

Also, the lack of information about the time period 8000 B.C. to 1 A.D. would influence the accuracy of this number greatly. There is also the whole religious versus scientific debate about the time of origin of the human race.

If we accept the guesstimate of 108 billion, then it would mean that 6.5 percent of all people ever born are still alive today!

(Source)