How Many People Were Born on the Same Day as Me?
Every day, somewhere between 350,000 and 385,000 babies are born around the world. One of those days was yours - and a specific, calculable number of people entered the world on that exact date, in that exact year, right alongside you.
The calculator above turns your birth date into that number: an estimate, built from global demographic data, of how many people share your exact birth date - and roughly how many of them are still alive today, based on cohort survival data for your age.
It's a strange thing to picture - hundreds of thousands of strangers, born in the same 24 hours you were, scattered across every country and language on earth. Below, we break down where that number comes from and how it shifts as a cohort ages.
Your invisible cohort
Picture your birth-day cohort as an invisible graduating class - hundreds of thousands of people who took their first breath the same day you did, then quietly moved through life in parallel. They started kindergarten the same year. They hit 16, 18, 21 around the same time you did. Right now, somewhere, thousands of them are having the exact same birthday party you are - just in a different time zone, a different language, a different life entirely.
That cohort shrinks as it ages, which is its own kind of statistic. Of everyone born on the same day as a 40-year-old today, our data estimates about 92.5% are still alive. By 70, that drops to roughly 62.1%. It's a quiet reminder that your birthday isn't just a personal date - it's a running tally, shared with a group of people you'll never meet but have been aging alongside the whole time.
How the calculator works
The estimate starts with total births in your birth year, drawn from global demographic data (the kind compiled in the UN's World Population Prospects). That yearly total is divided across the days of the year to get an average daily birth figure - in recent decades, that's typically about 350,000 to 385,000 births per day worldwide.
To estimate how many of those people are still alive, the calculator applies global cohort survival data: mortality tables that track the cumulative probability of surviving from birth to your current age. Multiplying the estimated birth-day figure by that survival probability gives the "still alive today" number shown for each age.
This is an estimate, not a census. Real daily birth counts vary by season, country, and even day of the week, and mortality varies widely by region. Treat the number as a well-informed approximation of scale, not an exact headcount.
Your birthday cohort by age
| Age | Born the same day (est.) | Cohort still alive |
|---|---|---|
| 10 | 383,060 | 96.9% |
| 18 | 382,623 | 96.3% |
| 25 | 379,260 | 95.5% |
| 30 | 381,421 | 94.7% |
| 40 | 371,671 | 92.5% |
| 50 | 343,825 | 88.1% |
| 60 | 323,014 | 79.2% |
| 70 | 276,339 | 62.1% |
| 80 | 250,137 | 35.2% |
Estimates from global birth counts for each birth year and cumulative survival from global mortality tables.
Frequently asked questions
How many people are born each day worldwide?
Roughly 350,000 to 385,000 babies are born globally every day, based on recent annual birth totals spread across the year. That works out to about 130-140 million births a year worldwide - more than the entire population of many countries, born in just twelve months.
How many people share my exact birth date?
It depends on your birth year and current age - the calculator above gives your specific number. As a reference point, our data estimates roughly 371,700 people share the exact birth date (month, day, and year) of a person turning 40 this year, of whom about 343,800 are estimated to still be alive today.
How many people share my birthday, ignoring the year?
If you just mean the same month and day across any birth year, it's about 1 in 365 people - roughly 22 million people worldwide, out of a global population of about 8.2 billion. That's a much bigger, looser group than people born on your exact date.
Are births spread evenly across the year?
No. Births cluster more in some months than others. In the United States, September is consistently the most common birth month, likely tied to conceptions around the winter holidays. Late December sees a noticeable dip, partly because scheduled deliveries are often pushed to avoid Christmas and New Year's.
How many people from my birth cohort are still alive?
It depends heavily on age. Our data estimates about 92.5% of a 40-year-old's exact-day birth cohort is still alive, dropping to roughly 62.1% by age 70 and about 35.2% by age 80. Younger cohorts see much smaller losses - around 95-97% survival through the teens and twenties.
What is the rarest birthday?
February 29 is the clear rarest - it only exists every four years, so roughly a quarter as many people are born on it as on a typical day. Among regular dates, December 25 stands out in the US for having notably fewer births, largely due to elective scheduling around the holiday.
How accurate is this estimate?
It's a well-informed approximation, not an exact count. The calculator divides your birth year's total births across the days of the year, then applies global cohort survival data for your current age. Real-world variation - by season, country, and region - means actual figures could differ somewhat from the estimate shown.
Sources
While you read this page
babies were born worldwide
This is one stat of 60+
Your full life report covers heartbeats, sleep, breaths, your place among everyone ever born, and dozens more — all from just your birth date.
Get your full life report