Koji
Boy name · #3392 in 2025 · Very rare
How old is the name Koji? In official American birth records, Koji has been tracked continuously since 1922, giving it 103 years of documented American history.
In 2025, 34 baby boys were named Koji, placing it at #3392 in the official national rankings. A decade ago it stood at #5289, so the name has been rising over the past ten years. Roughly one in every 52,941 boys born in 2025 was named Koji.
The 103-year story
Koji first appears in the Social Security records in 1922, when 5 boys received the name. Its all-time peak is essentially right now: 2025, with 34 babies and a rank of #3379. Names at their peak can keep climbing — or be one trend cycle from the long slide that eventually hits most popular names. Following the curve matters more than today's snapshot: a name's position on its rise-peak-decline arc is the best predictor of how common it will feel in a kindergarten class five years from now.
Babies named Koji per year. Source: Official national birth records.
Unlock the 5-year forecast and compare Koji against up to 5 other names.
Uniqueness: will there be another Koji in class?
On our rarity read — which blends how common Koji is today with its five-year momentum — the name reads as "very rare". A high score means genuine rarity — your Koji will likely be the only one in the room, with the occasional spelling-out as the price.
Where Koji is most common
State-level data for Koji is too sparse in 2025 to rank by rate — in most states its count falls below the SSA's per-state reporting threshold (counts under 5 are withheld).
Names like Koji
Statistically, parents drawn to Koji tend to be choosing among names with similar popularity arcs, era profiles, and sounds — the closest matches in our model are Khoi, Kavi, Kanai, Kazi, and Rafi.
KhoiKaviKanaiKaziRafiKoiDaniKairi
Rank history (last 25 years)
| Year | Babies named Koji | Rank |
|---|---|---|
| 2025 | 34 | #3379 |
| 2024 | 25 | #4200 |
| 2023 | 33 | #3474 |
| 2022 | 26 | #4089 |
| 2021 | 19 | #4936 |
| 2020 | 12 | #6620 |
| 2019 | 15 | #5813 |
| 2018 | 14 | #6036 |
| 2017 | 13 | #6338 |
| 2016 | 28 | #3776 |
| 2015 | 17 | #5289 |
| 2014 | 15 | #5733 |
| 2013 | 18 | #4981 |
| 2012 | 14 | #6001 |
| 2011 | 14 | #5945 |
| 2010 | 21 | #4517 |
| 2009 | 15 | #5800 |
| 2008 | 21 | #4540 |
| 2007 | 17 | #5210 |
| 2006 | 11 | #6904 |
| 2005 | 18 | #4631 |
| 2004 | 13 | #5813 |
| 2003 | 14 | #5271 |
| 2002 | 13 | #5395 |
| 2001 | 10 | #6445 |
Frequently asked questions
How old is the name Koji?
In official American birth records, the name Koji first appeared in 1922 (over 103 years ago), when 5 newborn boys received the name. It has been tracked in modern national records for 103 years.
Is Koji a popular boy name?
Koji ranked #3392 among boys in 2025 with 34 babies given the name — outside the top 500, making it an uncommon pick. Ten years earlier it ranked #5289.
When was the name Koji most popular?
Koji peaked in 2025, when 34 American boys received the name (ranked #3379 that year). That peak is current — the name is at or near its all-time high right now.
How rare is the name Koji?
In 2025, roughly 1 in 52,941 newborn American boys was named Koji. On our rarity scale (rarity blended with momentum) we classify it as "very rare".
Data source: Official American birth records, 1880–2025, national and state files. Counts reflect registered birth records for American families.