◌ ONE ORIGIN A world we share
Your birthday crowd

Your birthday crowd

Friends and family from several generations celebrating around a cake in a sunny garden.
One day, many lives

Millions of people can share your date. The calendar details around it are what make the feeling personal.

Pick a birthday and see both the global crowd and the smaller clues that still make the day feel like yours.

Give your birthday crowd a little confetti moment.

Share this part of the story

Share the text, the page, or a download card — whatever part of the experience feels like yours to pass on.

How this works · sources & limits

This estimate uses 8.2 billion people, the rounded 2024 population in UN World Population Prospects 2024, not a live population counter. Ordinary dates use population ÷ 365.25. February 29 uses population ÷ 1,461 as a simplified four-year model. Actual birthdays vary by place, season, leap-year rules, and age.

The extra calendar feedback uses the year you selected only to calculate things like weekday and day-of-year inside your browser. It does not change the crowd estimate, and nothing is stored or sent anywhere.

The complete answer is free. Inputs stay in this page’s memory; nothing is sent to a server or saved. Share only what you want others to see.

← Explore the map and the story behind One Origin

More ways we’re connected

Sixteen ways to put the same point — that every human line on Earth runs back to one place — in your own hands.

Your own numbers

Your birthday crowdA date you share with millions. Your family treeMore branches. Shared roots. Your place, real sizeA fairer view of somewhere you love. A moment we shareDifferent clocks. Happening together.

The deep record

Two chains, one continentMitochondrial Eve and Y-chromosomal Adam, drawn against time. The shared ancestor counterType a crowd. Find the ancestor every one of them shares. Count the hands between usFewer than 50 links separate any two people alive. Fourteen peoples, one patternStructural universals across five continents.

Shifting the frame

Footsteps of KinshipDrag 300,000 years of leaving Africa, one toolkit at a time. Root to BranchThousands of languages branching from African roots. The Deep Time MirrorYour face, aligned with the oldest skulls we have. The Deep History Time MachineWatch borders, cities and farms fade off the planet. The Great-Grandparent MultiplierYour family tree has to loop. Here is the maths. Stardust & SoilWhat you are made of, and where each atom was forged. The Borderless Night SkySame stars. Many skies. One imagination. The Reverse Migration PostcardA line from your city back to the Great Rift Valley.

Feel the pattern

The Converging RiversEvery river runs back to the Rift. Drag to pull a thread home. The Synchronized BreathOne atmosphere. Hold to slow and breathe with the globe. The Shared LexiconMama, water, fire: one breath, many scripts. The Erasure of BordersScroll to peel the modern map down to a starlit Africa. The Mirror of AgesMany shades, one composite face. Unify the spectrum.

What every human does

Everybody SingsMusic was in all 315 societies the census read. All of them. The Same FaceBorn blind, never seen a face — and the same smile on winning. Two Hundred MillisecondsTen languages, five continents, one fifth of a second.