March 13 had the fewest March births in these U.S. records from 1994 through 2014: 224,642. March 21 had the most, with 235,883. March 17 was second in March.
Compare March birthdays
March 13 had the fewest births and March 21 the most among March dates in these U.S. records. Choose two dates to see how far apart they are.
CDC/NCHS + SSA via FiveThirtyEight · 1994–2014 · 85,712,738 births
March 13
- Within March
- #31 of 31
- Across the whole year
- #337 of 366
- Recorded births
- 224,642
- Share of all births
- 0.262%
Both ranks count from most common (#1) to rarest. Ties share a rank.
March 13 had 4.8% fewer births than March 21 (224,642 versus 235,883).
Open March 13 in the birthday checkerAll 31 March birthdays ranked
Month rank compares only March dates. Overall rank compares all 366 dates, including February 29. #1 is most common in both columns.
| Date | Month rank | Overall rank | Births | Share of all births |
|---|---|---|---|---|
| March 1 | #3 | #176 | 234,495 | 0.274% |
| March 2 | #25 | #308 | 227,660 | 0.266% |
| March 3 | #6 | #188 | 233,405 | 0.272% |
| March 4 | #11 | #226 | 231,560 | 0.270% |
| March 5 | #12 | #228 | 231,388 | 0.270% |
| March 6 | #19 | #252 | 230,287 | 0.269% |
| March 7 | #5 | #185 | 233,850 | 0.273% |
| March 8 | #13 | #229 | 231,350 | 0.270% |
| March 9 | #28 | #316 | 226,813 | 0.265% |
| March 10 | #17 | #248 | 230,444 | 0.269% |
| March 11 | #18 | #251 | 230,308 | 0.269% |
| March 12 | #10 | #218 | 232,001 | 0.271% |
| March 13 | #31 | #337 | 224,642 | 0.262% |
| March 14 | #4 | #180 | 234,368 | 0.273% |
| March 15 | #9 | #213 | 232,129 | 0.271% |
| March 16 | #27 | #315 | 226,912 | 0.265% |
| March 17 | #2 | #171 | 234,700 | 0.274% |
| March 18 | #16 | #242 | 230,793 | 0.269% |
| March 19 | #20 | #257 | 230,048 | 0.268% |
| March 20 | #8 | #209 | 232,226 | 0.271% |
| March 21 | #1 | #149 | 235,883 | 0.275% |
| March 22 | #15 | #235 | 231,059 | 0.270% |
| March 23 | #29 | #323 | 226,193 | 0.264% |
| March 24 | #21 | #259 | 229,992 | 0.268% |
| March 25 | #14 | #232 | 231,202 | 0.270% |
| March 26 | #23 | #275 | 229,546 | 0.268% |
| March 27 | #22 | #270 | 229,682 | 0.268% |
| March 28 | #7 | #201 | 232,864 | 0.272% |
| March 29 | #24 | #285 | 229,032 | 0.267% |
| March 30 | #30 | #329 | 225,599 | 0.263% |
| March 31 | #26 | #314 | 226,937 | 0.265% |
Each March date occurs 21 times in this period, so ranking by births per occurrence gives the same order within this month.
Is March 17 a rare birthday?
Among March dates, no. March 17 had 234,700 recorded births, ranking #2 in March and #171 among all 366 birthday dates. #1 means the most births in each ranking.
March 17 had 1.9% more births than the average of March 10 and March 24 across this period. Those dates are one week before and after March 17, so all three fall on the same weekday within each year. March 17 exceeded that average in 20 of 21 years.
The birth files do not say why deliveries happened on a date. The comparison cannot show whether St. Patrick's Day affected them.
Which March dates had the fewest and most births?
March 13 ranks #337 across the year, while March 21 ranks #149. March 21 had 5.0% more births than March 13 across the period. The table above includes every March date.
March 18 had 230,793 births. It ranks #16 in March and #242 overall, near the middle of the March list. Compare it with March 17 or another date above.
How do the ranks work?
March rank compares 31 dates by total recorded births. Overall rank compares all 366. Every March date occurred 21 times in this period, so dividing each total by its number of occurrences would leave the order unchanged. The birth-share column divides a date's count by all births in the dataset, including births outside March.
Use the birthday checker or the full rarest-birthday ranking for dates outside March. The birth-month guide compares March as a whole with other months.
Sources and limits
These counts come from daily U.S. birth files compiled by FiveThirtyEight. The site uses CDC/NCHS records for 1994 through 1999 and SSA records for 2000 through 2014, excluding overlapping CDC years. March accounts for 7,147,368 births in the combined dataset.
The sources have different administrative coverage. These rankings describe historical U.S. births, not the world's births or everyone alive today. The weekday birth study shows why calendar patterns matter when comparing dates; the methodology explains the source selection and ranks.
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