Is September 21 a rare birthday? Very common
More common than 98% of all 366 dates.
September 21 in numbers
The odds, the star sign and the other dates that come with it.
Where September 21 ranks
From most common birthday to rarest, September 21 ranks in position #10, with 11,731 births a year. 356 other dates are rarer. 13 dates are within 1% of its count, anywhere from #2 to #15, so the exact position is a close thing.
September 21 through the years
Where it ranked in the United States, year by year.
common
September 21 in other countries
September 21 is the 10th most common birthday in the United States. It is among the 50 most common in 17 of the 26 other countries, and ranges from #2 in France to #286 in Argentina.
France
#2 of 366
2,286 births on an average September 21
INSEE, 1998–2024Chile
#3 of 366
798 births on an average September 21
DEIS, 1990–2017Mexico
#3 of 366
6,137 births on an average September 21
INEGI, 2017–2023Switzerland
#3 of 366
238 births on an average September 21
FSO, 1969–2025Slovenia
#4 of 366
61 births on an average September 21
SURS, 2000–2025Costa Rica
#6 of 366
190 births on an average September 21
INEC Costa Rica, 2014–2024Germany
#7 of 366
2,280 births on an average September 21
Destatis, 2014–2025Ireland
#7 of 366
184 births on an average September 21
CSO, 1980–2023Philippines
#7 of 366
5,309 births on an average September 21
PSA, 2006–2024Portugal
#10 of 366
325 births on an average September 21
INE Portugal, 1980–2025Guatemala
#11 of 366
1,070 births on an average September 21
INE Guatemala, 2018–2024Hungary
#12 of 366
351 births on an average September 21
KSH, 1970–2020England & Wales
#15 of 366
1,894 births on an average September 21
ONS, 1995–2025Japan
#17 of 366
3,008 births on an average September 21
e-Stat, 1996–2025Malaysia
#17 of 366
1,500 births on an average September 21
DOSM, 2000–2022New Zealand
#18 of 366
168 births on an average September 21
Stats NZ, 1980–2023Netherlands
#22 of 366
531 births on an average September 21
CBS, 1995–2025Finland
#63 of 366
148 births on an average September 21
Statistics Finland, 2010–2025Belgium
#64 of 366
338 births on an average September 21
Statbel, 1992–2025Denmark
#78 of 366
174 births on an average September 21
Statistics Denmark, 2007–2025Latvia
#96 of 366
56 births on an average September 21
CSB, 1996–2025Ecuador
#148 of 366
772 births on an average September 21
INEC, 2013–2023Peru
#151 of 366
1,213 births on an average September 21
INEI, 2019–2025Brazil
#163 of 366
8,058 births on an average September 21
DATASUS, 1997–2024Norway
#177 of 366
157 births on an average September 21
SSB, 2011–2025Argentina
#286 of 366
1,409 births on an average September 21
DEIS, 2018–2023
Famous people born on September 21
Ranked by how often people looked them up on Wikipedia last year.
Anne BurrellAmerican television chef · born 1969
Stephen KingAmerican author · born 1947
Alexander IsakSwedish footballer · born 1999
Cheryl HinesAmerican actress · born 1965
Bill MurrayAmerican actor and comedian · born 1950
Liam GallagherEnglish singer-songwriter · born 1972
Luke WilsonAmerican actor · born 1971
Shinzo AbePrime Minister of Japan (2006–2007; 2012–2020) · born 1954September against the other eleven
September 21 is the 8th most common of the 30 days in September. All September birthdays.
September is the most common month of the year
An average September day sees 11,448 births in the United States. September is the busiest month, January the quietest.
Quick answers
How many babies are born on September 21?
About 11,731 a year in the United States. It was at its most common in 1976, when 10,296 babies were born and it ranked #1 of 366; at its rarest in 1997, with 8,253 births at #311.
Is September 21 a common birthday?
In the United States, September 21 is the 10th most common of 366 dates, with about 11,731 births a year. That puts it among the more common birthdays.
What is the rarest September birthday?
In the United States, September 2: the 118th rarest of all 366 dates, with about 10,653 births a year. The most common September birthday is September 9, the most common of the year.
How precise is the ranking?
In the middle of the calendar it is not exact. 13 other dates are within 1% of September 21's count, spread from #2 to #15, so the position inside that group would shift with a different set of years. That band is the accurate answer; the rank is the simple one. At the ends — Christmas Day, New Year's Day — nothing is close.
Is September 21 rarer in other countries?
In some. It is rarer in 16 of the 26 other countries we hold daily records for. It is at its rarest in Argentina, at #286 of 366, and at its most common in France, at #2.
How this is counted
Every date is ranked by how many babies are born on it in the United States. Live births by day of birth from the CDC's National Center for Health Statistics, 1989–2024.
Updated October 2026