How Many Humans Have Ever Lived? And Why the Answer Is So Humbling
- MaryNell Goolsby
- 5 days ago
- 3 min read
Each one of us gets a short window of time—just one thread in this massive cosmic tapestry. But the truth is, that’s what makes our choices meaningful.
We get to decide: do we live in fear, regret, or pettiness? Or do we live with love, curiosity, and purpose—leaving behind something brighter for the next generation?
As I dive deeper into astronomy, I keep circling back to the same thought: if the universe is so vast, how small am I really? And not just me—but all of us, every human who’s ever lived.
So I started asking: How long have humans even been here? How many lifetimes have already passed? And how many people have walked this Earth before us? The answers, as you might guess, blew my mind.
🌍 How long have humans lived on Earth?
Modern humans—Homo sapiens—have been around for about 200,000 to 300,000 years.
That sounds long until you put it next to the age of the Earth (4.5 billion years) or the age of the universe (13.8 billion years). If the universe’s history were compressed into a single day, humans would appear in the very last second before midnight. We are unimaginably new.
⏳ How many lifetimes have passed?
When I thought about all the generations before us, it made me want to count lifetimes.
In ancient times, life expectancy was often 30–40 years.
By the 1800s, it hovered around 30 years globally.
Today, the global average is about 73 years.
So if we take 200,000 years of human existence:
At 40 years per lifetime → about 5,000 lifetimes.
At 70 years per lifetime → about 2,850 lifetimes.
I’m going to take the average and round up to say that there have been about 4,000 lifetimes.
That’s it. Just a few thousand lifetimes connecting us all the way back to the very first humans. Each one passing the torch to the next.
👥 How many humans have ever existed?
Here’s the staggering part: demographers estimate that about 117 billion people have lived on Earth.
Today, in 2025, about 8 billion of us are alive. Which means roughly 7% of all humans who have ever lived are alive right now. Think about that—we are part of one of the most crowded, connected chapters in human history.
👽 Are we really alone?
And if this is true of just our little planet, can we really believe we’re alone in the universe?
With hundreds of billions of galaxies, each filled with billions of stars and countless planets, it seems almost certain that life exists somewhere else. Maybe not as we know it—maybe not intelligent, maybe just simple forms—but the odds of life beyond Earth feel almost undeniable.
As Carl Sagan said: “The universe is a pretty big place. If it’s just us, seems like an awful waste of space.”
🌟 Why this humbles me
Thinking about all this doesn’t make me sad. It makes me grateful. It makes me want to live wide open, because our time here is so short.
I sometimes think back to my younger self. I had my children in my early 20s, and I loved that season of life. My marriage didn’t last, and for years I carried guilt over that. But when I think about the vastness of it all, I see it differently. Their father and I weren’t meant to stay together, but we were meant to create our children. And because of that, I now have a granddaughter who lights up my world. Without that path, she wouldn’t exist.
It reminds me that life isn’t about regret. It’s about understanding that everything happens for a reason. We each get just a brief window in the universe’s story. And when my time ends, I want to know that I chose love, joy, kindness, and purpose over fear, regret, or trying to impress others.
Because if 117 billion humans have walked this Earth before me—and billions more will after me—what better way to honor this short gift of life than to leave the world a little brighter because I was here?
💛 Honey
🌠 Further Reading & Resources
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