Birthday rarity calculator
Let's find out how rare your birthday is!
More birthday calculators
Explore more about your birthday
Use focused birthday tools for dates, ages, weekdays, countdowns, rarity comparisons, shared-birthday probability, and milestone patterns.
Birthday rarity guides
Compare the rarest and most common birthdays
See the dates at both ends of the calendar and learn how birthday patterns are compared.
Rarest birthdays
See which dates rank toward the rare end of the calendar and why Leap Day needs special treatment.
View rare birthdaysMost common birthdays
Explore the busier dates of the year and the seasonal patterns that can shape birthday frequency.
View common birthdaysCelebrity birthday matches
Find famous people who share your birthday and compare how rare their dates are in the same historical dataset.
Find celebrity matchesFrom 85.7 million recorded U.S. births
How common is my birthday?
The calculator shows both sides of the ranking, so you can see how rare or common your birthday is using recorded U.S. births from 1994 through 2014.
These rankings use historical U.S. daily birth records, not synthetic daily estimates. Compare the rarest birthdays and most common birthdays for the full tables.
Understanding your score
What makes a birthday rare?
Birthdays are not spread perfectly evenly across the calendar. Some seasons have more births than others, while major holidays and days affected by scheduling can have fewer. The calculator compares your month and day with the other 365 calendar dates in 85,712,738 recorded U.S. births from 1994–2014, then converts that rarity rank into a score.
A higher score means your date appears toward the rarer end of the historical ranking. A lower score means it appears toward the more common end. The recorded count, share, rank, and score all describe the same month-and-day comparison.
February 29 is different from every recurring date because it only appears in leap years. Its calendar rarity and its recorded birth total are related ideas, but they are not exactly the same measurement.
More than a number
Why People Love Exploring How Rare Their Birthday Is
Birthday rarity is a simple question with a surprisingly fun answer. People use the calculator to compare dates with friends and family, see whether a birthday falls near the rare or common end of the calendar, and discover famous people who share the same date.
The result also gives a familiar date a new bit of context. A birthday can land on a major holiday, appear in a busy stretch of the year, or sit near one of the quieter parts of the historical record. None of that makes one birthday better than another, but it does make the calendar more interesting to explore.
If you want to keep going, compare the rarest birthdays, the most common birthdays, or find celebrity birthday matches for your date.
Transparent birthday data
Where the Data Comes From
The birthday rarity ranking uses 85,712,738 recorded U.S. births from 1994–2014. The daily records come from CDC/NCHS data for 1994–1999 and Social Security Administration data for 2000–2014, combined into one non-overlapping historical series.
Those records are grouped by month and day to compare all 366 possible calendar dates. The site does not invent daily differences for countries where equivalent source data is not available, and it does not present the historical U.S. ranking as a worldwide birth distribution.
For the source files, ranking method, Leap Day treatment, and score calculation, see the full birthday rarity methodology.