How Many People Are Named Kaj?
An estimated 496 people in the United States have the first name Kaj. It is almost exclusively a male name. The average bearer is 24 years old, and Kaj peaked in popularity in 2006 with 20 births that year.
Below you will find a full statistical profile of Kaj as a first name in the United States, including gender data, a year-by-year popularity timeline going back to 1880, a decade breakdown, and state-by-state birth registrations. You can also check how many people share the full name Kaj paired with any surname.
Estimated Living Americans
496
About 1 in 691,037 people in the U.S.
Rarity
Very Rare
Predicted Gender
Male
100.0% confidence
Average Age
24
years old
Peak Year
2006
20 births
Total Registered
510
since 1880
Gender Distribution for Kaj
Kaj is almost exclusively a male name. Out of 510 total births registered, 100.0% were male.
Kaj as a male name
Ranked #6,007 in 2024
15 male births in 2024
Peak: 2006 (20 births)
Kaj: Popularity Over Time
SSA records for Kaj span from the 1950s to the 2020s, covering 8 decades of naming data. The most popular decade for this name was the 2000s, when 140 babies were registered. While Kaj is less common than at its peak in the 2000s, it remains a well-established name with steady registrations.
Kaj by Decade
How has Kaj tracked across different eras? The table below groups all SSA birth registrations into 10-year periods, with separate male and female counts. The colored bar shows each decade's share relative to the peak.
Kaj by State
Kaj + Last Name Combinations
How many people share a full name with Kaj as the first name? Click a combination below to see the estimate, or search any pairing.
Names Similar to Kaj
Other first names starting with K with a similar number of bearers.
Kaj: Questions and Answers
How many people in the U.S. are named Kaj?
We estimate approximately 496 people named Kaj are alive in the United States today. This is based on SSA birth records from 1880 to 2024, adjusted for mortality using CDC life tables. About 1 in 691,037 Americans share this first name.
Is Kaj a common name?
Kaj is classified as "Very Rare" and is more popular than 84.5% of all first names in the SSA database. A total of 510 births have been registered with this name since 1880.
When was Kaj most popular?
Kaj reached peak popularity in 2006, when 20 babies were given this name. The average age of a living person named Kaj is approximately 24 years old, reflecting when the name was most commonly given.
Is Kaj a male name?
Kaj is predominantly male. 100.0% of people with this name are male. See the gender breakdown above for full details.
How many Kaj Smiths are there?
To find how many people share a specific full name, we combine first name and surname frequencies. Try: Kaj Smith, Kaj Johnson, Kaj Williams. You can also search any combination on our homepage.
Where does this data come from?
Our estimates use Social Security Administration birth records (1880 to 2024), adjusted for survival using CDC 2023 life tables broken down by sex. The U.S. population figure (342,754,338) is from the Census Bureau's July 2025 estimate. Full methodology.
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