Koi
Koi is a boy's name that peaked in 2022, when it was the 2,243rd most popular in the United States. It is given to both boys and girls. In 2025 it ranked 3,036th. About 1,500 Kois are alive in the United States today, and half of them are over 7.
Popularity, 1880–2025
girls named Koi boys named Koi
Girls and boys called Koi
years more girls than boys years more boys than girls
Both, throughout, without either side ever taking it over: 669 girls and 813 boys in all, and in 2025 the split was 84 to 40.
The girls’ share of each year’s babies of the name, in the 20 years in which at least 25 babies got it. The line touches the middle more often than there are crossings marked: a year or two on the other side is not a name changing hands, and only a move that holds for 5 counted years and reaches 60/40 is recorded as one. All 581 names that changed sex.
By the numbers
- Total US births
- 1,482
- Estimated living today
- 1,500
- Median age today
- 7
- Peak year
- 2022
- Best rank
- 2,243rd
- Rank in 2025
- 3,036th
- First recorded
- 1995
- Girls / boys
- 669 / 813
How old the living Kois are
born that year still alive today
Of the 1,482 babies given the name since 1995, about 1,500 are alive — 99 in every hundred. Roughly 1,300 of them are children and 0 are 65 or over. The dotted line is the median: half were born before 2018 and half after.
An estimate, not a count. SSA births aged forward through SSA cohort life tables, which know nothing about who left the country or arrived in it — so for a name that mostly came to America rather than being born in it, this is a floor rather than a figure. Where you fall among living Americans.
Where Koi is most common
Relative to how many babies each state records, Koi is most concentrated in Louisiana (11.8×), Georgia (6.8×), Florida (4.7×), Texas (3.2×).
Total births recorded in each state since 1910. Browse names by state.
Names of 2022
The most popular boys’ names the year Koi peaked:
Koi elsewhere
| Country | Spelling | Births | Best rank |
|---|---|---|---|
| England and Wales boys | Koi | 3 | 4,810th |
Counts come from each country's own records and are not comparable with the US figures above, which cover different years and a different definition of a recorded name. Where a country writes the name several ways, the spellings are added together and the most common is shown. A row marked name registrations is counting something else: Portugal ranks each of a child's two given names separately, so a girl registered Maria Leonor is in both the Maria row and the Leonor row, and that figure is not a number of children.
Try it on yourself
Source: US Social Security Administration, national and state baby-name files, 1880–2025. Counts include only births registered with the SSA, and names with fewer than five births in a year are not published. The living estimate applies SSA cohort life tables to those births; it counts people born in the United States, so it misses anyone who arrived later and anyone who has left.