is it mathematically possible to estimate how many humans have ever lived?


Question from an actual kid, though she was eight, not five. Hopefully there’s an explanation more detailed than just “no” I can pass on to her.

In: 509


Yes, and the answer is a bit over 100 billion, meaning that about 8% of humans who have ever lived are alive today. This is just an estimate, and it’s subject to a decent amount of error, but it’s probably accurate to within 10% or so. Most of those people lived in the last 2000 years or so, and records from that era of human history are good enough to provide at least reasonable estimates. Only a few billion, or about 10% of humans, lived before the development of agriculture.



There is a Radio Lab episode about this! I thought on balance they said the total number of people who had lived was almost the same as the number of people living today, (caveat it’s been a while since I listened to it.

Here is the link: [Radio Lab – “Body Count”](

EDIT: they were talking about *just* the USA. They say there will be more dead than alive in 2060, but for now they claim there are more alive than dead.