Koi
Koi is given to both girls and boys: 84 girls and 40 boys were given it in 2025 (#2,207 among girls’ names and #3,060 among boys’, #3,064 among all names counting both); 1,482 Americans have been recorded with it since 1995 (Social Security Administration, published May 2026). Girls have outnumbered boys among babies named Koi every year since 2023.
An estimated 1,470 Americans named Koi and born in the U.S. are alive in 2026 (99% of everyone recorded); the median is 8 years old and half are between 4 and 15.
Girls and boys together; gaps are years SSA did not record (fewer than 5 births).
Births of Koi by year: SSA national baby-name file, 1880-2025, published May 8, 2026. SSA’s notes on the data.
How popular is Koi?
#3,060 among boys’ names, 2025
Koi rose from #4,478 in 2015 to #3,060 in 2025 among boys’ names; its share of boys born rose from 11.5 to 23.4 per million.
127 babies in 2023, the peak
Koi peaked in 2023, when 127 babies were given it (55 boys, #2,459 among boys’ names). The 124 births of 2025 (girls and boys) are 98% of that peak.
Births by sex.
| Year | Girls | Girls’ rank | Boys | Boys’ rank |
|---|---|---|---|---|
| 2025 | 84 | #2,207 | 40 | #3,060 |
| 2024 | 54 | #3,034 | 49 | #2,693 |
| 2023 | 72 | #2,479 | 55 | #2,459 |
| 2022 | 43 | #3,624 | 64 | #2,258 |
| 2021 | 66 | #2,621 | 53 | #2,515 |
| 2020 | 34 | #4,121 | 47 | #2,677 |
| 2019 | 33 | #4,302 | 39 | #3,077 |
| 2018 | 32 | #4,406 | 34 | #3,334 |
| 2017 | 25 | #5,255 | 26 | #4,042 |
| 2016 | 19 | #6,554 | 27 | #3,934 |
Every recorded year (30)
| Year | Girls | Girls’ rank | Boys | Boys’ rank |
|---|---|---|---|---|
| 2015 | 18 | #6,861 | 22 | #4,478 |
| 2014 | 22 | #5,895 | 34 | #3,272 |
| 2013 | 26 | #5,223 | 34 | #3,238 |
| 2012 | 15 | #8,035 | 25 | #4,078 |
| 2011 | 14 | #8,430 | 40 | #2,932 |
| 2010 | 20 | #6,520 | 34 | #3,277 |
| 2009 | 10 | #11,107 | 20 | #4,848 |
| 2008 | 13 | #9,266 | 25 | #4,092 |
| 2007 | 11 | #10,504 | 17 | #5,329 |
| 2006 | 15 | #8,063 | 19 | #4,784 |
| 2005 | 7 | #13,783 | 15 | #5,447 |
| 2004 | 6 | #15,175 | 14 | #5,650 |
| 2003 | 9 | #10,891 | 12 | #6,079 |
| 2002 | 9 | #10,686 | 14 | #5,274 |
| 2001 | 7 | #12,790 | 12 | #5,871 |
| 2000 | under 5 | 9 | #7,140 | |
| 1999 | 5 | #15,704 | 8 | #7,541 |
| 1997 | under 5 | 10 | #5,894 | |
| 1996 | under 5 | 8 | #6,840 | |
| 1995 | under 5 | 7 | #7,430 |
Ranks: girls’ names and boys’ names ranked separately in each year’s SSA file; “under 5” is a year SSA did not list the name for that sex.
Is Koi a boy’s or a girl’s name?
Of the 1,482 Americans recorded as Koi, 45% are girls and 55% boys.
Years with fewer than 20 babies given the name are left blank.
Girls and boys named Koi: the SSA national file counts each sex separately.
How many people are named Koi, and how old are they?
1,470 alive in 2026, estimated
That is 99% of the 1,482 Americans ever recorded as Koi. The median Koi alive today is 8 years old; half are between 4 and 15.
The 2020 Census counted 841 people named Koi (355 women and girls, 486 men and boys). SSA’s births carried forward to Census day, April 1, 2020, predict 834 born in the U.S. The Census count is 1% above that prediction.
Alive today, by age
Alive today, by generation
| Generation | Born | Alive |
|---|---|---|
| Millennials | 1981-1996 | 15 |
| Generation Z | 1997-2012 | 410 |
| Generation Alpha | 2013-2025 | 1,050 |
An estimate, not a count. SSA’s files count people born in the United States who received a Social Security number, so anyone born abroad is not in them; before 1937 most people got a number as adults, and their survival is counted from that age.
Living estimate: SSA births carried forward with the survival rates in SSA’s cohort life tables (2024 Trustees Report) for each birth year and sex. How the estimate is made. Count: Census Bureau, first names in the 2020 Census (released April 14, 2026; names reported 100 or more times, with the Bureau’s disclosure-avoidance adjustment).
Names spelled alike
Of these 8 names spelled alike, given to 32,978 babies since 1880, Koi is the third most given (4.5% of them). In 2025 it was given to 124 of their 2,052 babies (6.0%), again the third most given.
Spelled alike: names in the SSA national file with the same pattern of letters and sounds and at most two letters apart, and Wiktionary’s listed forms; births since 1880 and in 2025, and each name’s peak year, from the SSA national file, published May 8, 2026. Some are separate names, not spellings of one.
Names that rose and fell in the same decades as Koi
Names whose births rose and fell across the same decades, measured on each decade’s share of births.
Similar histories: each decade’s share of births, from the SSA national file, 1880-2025, published May 8, 2026. SSA’s notes on the data.
More about Koi and names like it
- Compare Koi and CoyBirths, ranks, peak and the living estimate side by side.
- The most given names of the 2020sKoi peaked in 2023.
- Texas’s most given namesThe state where SSA recorded the most babies named Koi since 1910.
- The top names of 2023The year the most babies were named Koi.
- The names of Generation AlphaMost people named Koi alive today were born 2013-2025.
- Names starting with KMost given first.