Koi Boy & girl
How popular is Koi?
#2,194 girl name in 2025
84 baby girls were named Koi in the US in 2025, making it the 2194th most popular girl name. Another 40 boys got the name (#3,035 for boys).
Koi popularity over time
Boys Girls
| Rank in 2025 | #2,194 for girls (▲ 819 from 2024) |
|---|---|
| Babies in 2025 | 84 girls, 40 boys |
| 10-year trend | Rising fast (+367% babies vs 2015) |
| Earlier ranks | #6,719 in 2015, #4,077 in 2020 |
| Peak year | 2025 (84 girls) |
| Highest rank | #2,194 in 2025 |
| First recorded | 1999 |
| Boys vs girls (last 10 years) | 48% boys, 52% girls |
| Chance a classmate shares it | 0.1% in a class of 25 kids born in 2025 |
Koi counting every spelling
Social Security counts each spelling as its own name. Adding together the spellings that sound alike, the Koi family of names ranked #1,525 for girls in 2025 (#1,871 the year before), with 102 babies in all.
| Spelling | Girls in 2025 | Share |
|---|---|---|
| Koi | 84 | 82% |
| Coi | 18 | 18% |
Spellings are grouped by how they sound, using our own rules, so a few groupings may not match how your family says the name.
Where Koi is most popular
Babies named Koi per 1,000 girls born in each state, 2021 to 2025. Darker means more common.
Koi by decade
Girl names about as popular as Koi
Questions
- Is Koi a boy or girl name?
- Koi is used for both. Over the last 10 years, 48% of babies named Koi were boys and 52% were girls.
- How popular is the name Koi?
- 84 baby girls were named Koi in the US in 2025, making it the 2194th most popular girl name. Another 40 boys got the name (#3,035 for boys).
- When was Koi most popular?
- Koi peaked in 2025, when 84 girls were given the name. Its highest rank was #2,194 in 2025.
- How many people are named Koi?
- 1,482 babies have been named Koi in the US since 1880. We estimate about 1,473 of them are alive in 2026, with a median age of 8.
- Where is Koi most popular?
- From 2021 to 2025, Koi was most common in Louisiana, at 0.2 of every 1,000 girls born there.
Source: Social Security Administration baby name data, 1880 to 2025 (names given to at least 5 babies of a sex in a year). Living-people and median-age figures are our estimates using US life tables. How we calculate.