How this is counted

RareBirthday ranks every calendar date by how many babies are born on it. Rank 1 is the most common birthday, 366 the rarest. Each date is the average number of births on that date over the years of records, and February 29 is averaged over its leap years only, so leap day is measured on the days it exists. Every page is written around the United States, and each date page also shows the same date in 26 other countries. Most birthday rankings online still use the same public file, which stops in 2014; ours rests on a special NCHS tabulation of every US birth from 1989 to 2024 and on official records from 26 other countries.

United States

The rank uses live births by day of birth from the CDC's National Center for Health Statistics for every day from 1989 to 2024: 142,623,862 births over 13,149 days, one source and one method, with every annual total equal to the published national count. The NCHS Division of Vital Statistics prepared these daily counts for RareBirthday in September and October 2026. Counts for 1989–2003 also appear in Vital Statistics of the United States, Volume I, Natality; NCHS has not published the daily counts from 2004 on.

National Center for Health Statistics. National Vital Statistics System, natality data for 1989–2008 and 2009–2024, unpublished tabulations prepared by the Division of Vital Statistics. October 5 and September 16, 2026.

The chart of each date's rank year by year runs from 1969 to 2024: NCHS's individual birth records for 1969–1988, then the counts above, 213,109,370 births in all.

Other countries

Each country is ranked on its own records, the same way as the United States, so a date is only ever compared with other dates in the same country. A country is included when its records hold at least 500,000 births; below that, a single date's rank is mostly chance. Some series come from tables the statistics office publishes, some we counted ourselves from individual birth records, and several offices prepared a table for RareBirthday on request. Others told us they do not count births by day, or cannot release those counts: Albania, Bulgaria, Georgia, Hong Kong, Macao, Serbia and Ukraine.

Weekdays and precision

Scheduled deliveries happen on weekdays, so a date that falls on a Saturday or Sunday records fewer births that year. In the middle of the calendar, many dates sit within 1% of each other, so a rank there could shift by a few places with a different run of years. Where that happens, the date page says how many dates sit within 1% of its count.

People

Everyone Wikipedia lists as born on the date, ordered by 2025 article pageviews. A small number of names are left off the public list where they would make a birthday page an unwelcome place to land.

Using these numbers

You are welcome to quote any figure on RareBirthday and to use its charts and illustrations, in print or online, with credit to RareBirthday and a link to the page they come from. The birth counts behind them belong to the statistics offices listed above, and their own terms apply to the counts themselves.

Decisions that change a rank or a source are dated on the changelog.

Updated October 2026