How rare isyour birthday?

How rare is

Your birthday

MONTH

AugustSeptemberOctober

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DAY

8910

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Reveal mine

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Rarer than

Your birthday twin is out there.

The 50–50 crowd

Other people for at least a 50–50 chance of one sharing your birthday.

Try a crowd: 23 other people

Someone matches your birthday

Any two of them match each other

A match somewhere in the group is much easier to find than a match with one specific birthday.

Independent draws from the U.S. sample. The group excludes you; “any two” compares people within that group. Shared month and day, regardless of year.

of the top 10 birthdays are in September.more September 9 births than Christmas Day births.

U.S. · 1994–2014

How much data is behind this?

225.5Mrecorded births in the daily-count collection

Your main result uses 85.7M U.S. births. The wider explorer covers several countries and time periods.

U.S. · 42 observed years160,176,743

England & Wales · 1995–202520,231,846

Metropolitan France · 1968–202342,899,901

France · 2025–July 20261,015,108

Denmark · 2007–20251,145,696

225,469,294 births across 54,634 dated counts. Overlapping U.S. years are counted once. Countries, coverage and periods differ; this is a collection total. Recent France includes a separately labeled partial year.

Also included: 4,392 famous birthdays, a snapshot of 6,025,603 Danish residents, and birth-hour patterns from 3,628,934 U.S. births in 2024. These are separate collections, counted apart from the daily-count total.

Compare countries, years and more patterns →

How the numbers are calculated

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