Birthday Rarity

🎂 How Rare Is Your Birthday?

Every day of the year, ranked from the most common birthday (#1) to the rarest (#366), using 2000–2014 US birth records. Pick your date to see where it lands — then read on for why September wins and Christmas loses.

August 31 is the

#73

most common birthday of 366

About 11,825 babies were born on this date each year in the US — more than 80% of all other days.

August 31 is on the common side — more births than most days.

Share on X Facebook

🎂 What’s your birthday?

Pick your date to see your full birthday profile — zodiac, life path and more.

The shape of the year: September is the busiest month

Births are not spread evenly. Averaged over 2000–2014, the busiest month is September (11,999 births per day) and the quietest is January (10,909). 7 of the 10 most common birthdays fall in September, and the single most common date is September 12.

  1. January 10,909
  2. February 11,152
  3. March 11,125
  4. April 11,024
  5. May 11,173
  6. June 11,474
  7. July 11,721
  8. August 11,914
  9. September 11,999
  10. October 11,404
  11. November 11,131
  12. December 11,171

Average US births per calendar day in each month, 2000–2014. Leap day excluded from February’s average.

Why the rarest birthdays are holidays

Set leap day aside and the rarest birthday in the US is December 25 — about 6,438 births per year, roughly 2.0× fewer than September 12. 5 of the ten rarest dates sit between Christmas Eve and January 2, and Independence Day and Thanksgiving week fill most of the rest.

The usual explanation is that a large share of deliveries are scheduled (inductions and caesareans), and hospitals don’t schedule them on holidays, so those births shift to the surrounding weekdays. The dataset records when babies were born, not why, so treat that as the standard reading rather than something these numbers prove.

February 29 is a different story: it exists only every four years, so its per-year average (2,791) is about 4.6× below the top — an artefact of the calendar, not of parents avoiding it.

🔼 The 10 most common birthdays

  1. #1September 1212,735
  2. #2September 1912,696
  3. #3September 2012,542
  4. #4December 1912,446
  5. #5September 1012,445
  6. #6December 2012,440
  7. #7September 1812,426
  8. #8August 812,422
  9. #9September 2612,421
  10. #10September 1712,386

🔽 The 10 rarest birthdays

  1. #366February 29leap day2,791
  2. #365December 25Christmas Day6,438
  3. #364January 1New Year’s Day7,735
  4. #363December 24Christmas Eve8,034
  5. #362July 4Independence Day8,815
  6. #361January 2day after New Year’s9,606
  7. #360December 26Boxing Day9,874
  8. #359November 23Thanksgiving week9,875
  9. #358November 25Thanksgiving week9,978
  10. #357November 27Thanksgiving week10,013

What about the 13th?

The 13th ranks in the rarer half of the year in 8 of the 12 months — but the pull of September is stronger than any superstition: September 13 still comes in at #19.

About the data

Ranks are built from US Social Security Administration birth records for 2000–2014 (15 years), as published by FiveThirtyEight. Each date’s figure is the average number of US births on that calendar day per year; the ranking is the plain order of those averages — no smoothing, no modelling. The pattern (a late-summer peak, holiday troughs) is broadly similar in other countries, but the exact ranks are US-specific.

Not fortune-telling: this page reports birth counts only. About our data