Baby Names US
boys' name ★ peaked 2006

Kaj

Gender Boy Rank 2025 #12,947

Kaj is a given name of unknown origin, particularly common in the Nordic countries, loaned from the Continent.

Rank 2025
#12,947
among boys · ↓6,914 vs 2024
Babies in 2025
5
named Kaj
How common
1 in 341,615
boys born in 2025
Peak year
2006
20 babies
All-time total
515
#7,764 all-time among boys
First recorded
1956
in Social Security records

Kaj popularity over time

515 babies have been named Kaj since 1956, according to official Social Security records. Switch measure to see births per year or the yearly rank.

Measure
Births per 1,000 babies of that sex, comparable across eras
00.010.010.0218801900192019401960198020002020Peak 2006Boys

By decade. Change compares yearly averages, so the current partial decade is on equal footing. Best rank is the name's best yearly rank within the decade.

Decade Boys Per year Change Best rank
1880s – – – –
1890s – – – –
1900s – – – –
1910s – – – –
1920s – – – –
1930s – – – –
1940s – – – –
1950s 5 1 – #4,205
1960s 30 3 +500% #3,447
1970s 26 3 -13% #4,788
1980s 54 5 +108% #3,572
1990s 74 7 +37% #4,750
2000s 140 14 +89% #4,601
2010s 134 13 -4% #4,905
2020s (to 2025) 52 9 -35% #6,033

The story of Kaj

Kaj is rare for boys in the United States, ranked #12,947 in 2025 with 5 babies given the name. It is currently declining compared with a decade ago.

Since 1956, 515 American babies have been named Kaj. Its peak came in 2006, when 20 newborns received the name, the signature sound of the 2000s.

The chart above shows the full history: the popularity view (births per 1,000 babies) is the honest comparison across generations, since total US births have changed enormously since 1880. Switch to the rank view to see where Kaj stood among all boys' names in any year, or use the compare tool to plot it against other names.

How old are people named Kaj?

The median living Kaj is about 20 years old; half are between 12 and 32. An estimated 500 people named Kaj are alive in the United States today.

median 20 020406080100

Estimated from births per year and Social Security period life tables; an approximation of the living age distribution, by age in years.

Kaj year by year

Every year since 2001, and five-year steps back to 1880. Rank is within each sex.

Year Boys Boys rank
2025 5 #12,947
2024 15 #6,033
2023 8 #9,346
2022 6 #11,573
2021 10 #7,862
2020 8 #9,129
2019 8 #9,304
2018 17 #5,423
2017 10 #7,864
2016 11 #7,378
2015 15 #5,870
2014 10 #7,846
2013 12 #6,815
2012 16 #5,601
2011 19 #4,905
2010 16 #5,608
2009 20 #4,839
2008 15 #5,926
2007 11 #7,345
2006 20 #4,601
2005 10 #7,399
2004 10 #7,269
2003 14 #5,410
2002 15 #5,026
2001 10 #6,708
2000 15 #4,915
1995 7 #7,382
1990 8 #6,131
1985 6 #6,161
1980 – –
1975 6 #5,122
1970 – –
1965 – –
1960 – –
1955 – –
1950 – –
1945 – –
1940 – –
1935 – –
1930 – –
1925 – –
1920 – –
1915 – –
1910 – –
1905 – –
1900 – –
1895 – –
1890 – –
1885 – –
1880 – –

Famous people named Kaj

The most globally famous bearers of the name, ranked by fame across Wikipedia editions (Pantheon project, MIT).

  1. 1 Kaj Munk Kaj Munk Danish playwright and pastor (1898–1944) 19th century
  2. 2 Kaj Leo Johannesen Kaj Leo Johannesen Faroese politician (born 1964) Contemporary
  3. 3 Kaj Franck Kaj Franck Finnish artist and designer (1911–1989) Contemporary

Portraits from Wikipedia (Wikimedia Commons).

Frequently asked questions

Quick answers about Kaj, drawn from the same Social Security data as the charts above.

How old is the average Kaj?

The median living Kaj is about 20 years old. Half of all living Kajs are between 12 and 32 years old.

How many people named Kaj are alive today?

An estimated 500 people named Kaj are alive in the United States, based on 515 recorded births and Social Security life tables.

What does the name Kaj mean?

Kaj is a given name of unknown origin, particularly common in the Nordic countries, loaned from the Continent.

How popular is the name Kaj in 2025?

Kaj ranked #12,947 among boys' names in the United States in 2025, with 5 babies given the name, according to Social Security Administration data.

How many people are named Kaj?

515 babies have been named Kaj in the United States since 1956, based on Social Security card applications.

When was the name Kaj most popular?

Kaj peaked in 2006, when 20 newborns received the name.

Is Kaj a boy or girl name?

Kaj is overwhelmingly a boy's name: 100% of babies with the name.

Is the name Kaj rising or falling?

Kaj is declining, less popular now than a decade ago.

Who are famous people named Kaj?

Well-known people named Kaj include Kaj Munk (writer), Kaj Leo Johannesen (politician), Kaj Franck (designer).

Names like Kaj

Names that sound and feel close to Kaj: shared sounds, similar era, similar popularity. Each links to its full history.

Compare Kaj with similar names → More names starting with K →