Koji
About 645 American babies have been named Koji since 1922, most of them around 2025. In 2025 it ranked 3,379th. About 620 Kojis are alive in the United States today, and half of them are over 15.
Popularity, 1880–2025
boys named Koji
By the numbers
- Total US births
- 645
- Estimated living today
- 620
- Median age today
- 15
- Peak year
- 2025
- Best rank
- 3,379th
- Rank in 2025
- 3,379th
- First recorded
- 1922
How old the living Kojis are
born that year still alive today
Of the 645 babies given the name since 1922, about 620 are alive — 95 in every hundred. The dotted line is the median: half were born before 2010 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 the name comes from
Origin Japanese
Borrowed from Japanese こうじ.
Etymology from Wiktionary, used under CC BY-SA 4.0.
Notable Kojis
- Koji Nakata (born 1979)Japanese association football player
- Koji Yamase (born 1981)Japanese association football player
- Koji Noguchi (born 1970)Japanese association football player
- Koji Sasaki (born 1936)Japanese association football player
- Koji Tanaka (1955–2026)Japanese association football player and manager
- Koji Funamoto (born 1942)Japanese association football player
- Koji Miyata (born 1923)Japanese association football player
- Koji Kondo (1972–2003)Japanese association football player
People named Koji with articles in the most Wikipedia languages. Data from Wikidata (CC0).
Where Koji is most common
Relative to how many babies each state records, Koji is most concentrated in California (9.2×).
Total births recorded in each state since 1910. Browse names by state.
Names of 2025
The most popular boys’ names the year Koji peaked:
Koji elsewhere
| Country | Spelling | Births | Best rank |
|---|---|---|---|
| England and Wales boys | Koji | 32 | 3,334th |
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.